Heavy equipment management practices and problems in Thai highway contractors

Thanapun Prasertrungruang and B.H.W. Hadikusumo


Introduction

Highway construction business is a sector that relies primarily on high utilisation of machinery. Equipment is thus one of the key factors for improving contractor’s capability in performing their work more effectively and efficiently (Day and Benjamin, 1991). By utilising machinery, an extensive volume of work can be completed in a shorter period of time and within the project schedule. However, in managing construction equipment, contractors are invariably plagued with several difficulties such as huge capital investment in the acquisition phase, which usually constitutes a major financial burden. Procurement of major construction equipment not only costs as high as 36 per cent of the total construction project cost, but also causes a high delivery time uncertainty, which may disrupt the construction schedule (Yeo and Ning, 2006). In the operational phase, contractors are often faced with problems relating to high rate of equipment breakdown and accident resulting from unskilled operator abuse (Stewart, 2000; Edwards and Holt, 2002; Edwards and Nicholas, 2002). Poor training of equipment operators is often claimed as a major cause of equipment-related accidents (Gann and Senkar, 1998). In the maintenance phase, proper maintenance management of construction equipment is never over-emphasised since the cost and time that exceed the designated budget or schedule on projects are often resulted from poor machine maintenance practices. However, over-maintenance of equipment is undesirable as well (Vorster and De La Garza, 1990; Edwards et al., 1997). In the disposal phase, determining equipment economic life and timing for replacement is often problematic because such decision is influenced by various factors such as machine obsolescence and efficiency (Vorster, 2005).

Effective equipment management practices not only increase production time and equipment availability, but also maximise the company profit by reducing several costs such as those from costly downtime (Edwards et al., 1998a). However, researches in the field of equipment management practice, particularly in the construction context, have been rare (Edwards et al., 1998b). This research was conducted in order to investigate current practices and problems on equipment management as well as to identify practices that are capable of mitigating equipment management problems from Thai highway contractor’s perspectives. Since machine weight is one of the major indicators of equipment downtime and maintenance cost (Edwards et al., 2000a, b; Edwards et al., 2002), only five types of heavy construction equipment were selected in this study (refer to Table I). It is believed that a study on heavy equipment management practices would contribute great benefits for highway contractors in helping them manage heavy equipment successfully.

Contractor heavy equipment management practices
In this research, contractor heavy equipment practices have been categorised into four significant stages based on machine lifecycle, i.e. acquisition, operations, maintenance and disposal.

Equipment acquisition practice (EAP)

It is generally accepted that smart acquisition practices fuel company success. Contractors always have vested interest in ensuring that their invested equipment are properly used, maintained and managed (Mitchell, 1998). In practice, capital conservation is a major factor for most companies in deciding to buy, lease, or rent on an installment plan (Sutton, 2003). Most companies, regardless of size, tend to prefer a purchasing strategy than other alternatives (Stewart, 2002a). To fulfill short-term equipment demand, most contractors realise the importance of rental machine utilisation (Stewart, 2002b). In the case of high workload during a peak construction cycle, leasing approach, which may come as a package with maintenance services from dealers, may be deemed appropriate (Stewart, 2002c).

Equipment operational practice (EOP)

An equipment operator is the person in the construction organisation who has the most influence on equipment costs (Stewart, 2001). Quality output can be partly achieved through skilful operators working with machines that are in good operational condition, thus educating equipment operators is one of the most important policies and thus holds great cost-saving potential (Wireman, 1999). Better channels of training can be obtained from various sources such as dealers (Stewart, 1998) and external agencies (Edwards and Holt, 2002). Systematic record-keeping is another practice that can generate valuable management guidelines, particularly in equipment planning and maintenance strategy (Marquez and Herguedas, 2004). Contractors must continually evaluate machine records in order to determine what actions are needed.

Equipment maintenance practice (EMP)

Maintenance of equipment is essential to contractor’s profitability because it not only extends the useful life of the equipment but also controls the machine availability at a minimum cost. Nevertheless, equipment maintenance is the most neglected aspect. Successful maintenance management can be achieved through well-developed maintenance programs (Tavakoli et al., 1990; Shenoy and Bhadury, 1998). Maintenance programs can be classified into several forms based on their complexity such as corrective maintenance, preventive maintenance and predictive maintenance (Gopalakrishnan and Banerji, 1991). Maintenance should not be viewed as a cost, but as an investment that can be linked to the company’s future revenue growth (Sutton, 2001).

Equipment disposal practice (EDP)

The last stage of machine lifecycle is disposal stage, in which two major decisions concerning equipment have to be made, i.e. timing of replacement and equipment economic life expectancy (Douglas, 1975). There are various factors affecting the timing of replacement: machine efficiency, capital availability, investment costs, commencement of new projects, profits accrued from use, tax expense, depreciation, economic analysis, obsolescence costs, and downtime cost (Hinze and Ashton, 1979; Schexnayder and Hancher, 1981; Tavakoli et al., 1989).

Research method

Data collection
This research involves a questionnaire survey by mail to collect the necessary data on equipment management practices and problems of highway contractors in Thailand. According to the Department of Highways (DOHs) of Thailand, highway contractors can be categorised into five classes (i.e. extra first, first, second, third, and forth classes) based on construction experience and company resources (i.e. equipment, finance and workforce). For the sake of data analysis, it was decided to reclassify contractors into three groups (i.e. large, medium and small). Large contractor group represents the companies registered in the extra first class, medium contractor group includes those registered in the first and second classes and small contractor group comprises of companies registered in the third and forth classes.

At the first stage of the questionnaire development, a pilot test, using a semi-structured questionnaire, was conducted to test for the applicability of the tool. The selected samples for the pilot test comprise of equipment managers from ten different companies (i.e. four large, three medium, and three small contractors). Once the pilot test was completed, a valid questionnaire was then prepared and data collection was started. The questionnaire has been divided into three parts. The first part is an introductory section that includes questions related to the respondents and their company profile. In the second part, the respondents were asked to give a score on the frequency level for each of the 73 variables concerning equipment management practices (see Table I). Responses are on a four-point scale (never = 0, seldom = 1, often = 2 and always = 3). In the third part, the respondents were asked to specify the impact/significant level for each of the 20 equipment management problems that actually affect their companies on a five-point scale (not significant = 0, somewhat significant = 1, moderate significant = 2, significant = 3 and very significant = 4). Questionnaires were mailed to the respondents on a basis of random stratified sampling technique.

Conclusion

To some extent, heavy equipment management practices vary considerably among different highway contractor sizes. Large firm’s practices tend to be much different from those of the smaller firms, whereas medium and small contractors’ practices are more likely to be similar. Large contractor’s practices tend to be more successful in minimising equipment management problems. In order to diminish equipment problems, particularly downtime, the importance of performing preventive maintenance should be strictly emphasised. Adoption of professional services (e.g. maintenance and training) from external agencies such as dealers is also recommended if such tasks are not the company’s core competency. Moreover, equipment should be disposed of or replaced once it becomes inefficient or generates less productivity with high repair cost.

The foregoing practices could be considered effective because it significantly reduces major equipment management problems. Therefore, adaptation and implementation of such practices by contractors are strongly suggested. Nevertheless, this research focuses only on equipment management practices and problems of several types of large heavy machines for highway construction. Practices and problems relating to small machines or even equipment utilised in other industries are probably different from this study and thus could be the area for future research.
This paper was published in the journal “Engineering, Construction and Architectural Management Vol. 14 No. 3, 2007 pp. 228-241”. Full article is available upon request. Abstract is also posted.

Abstract

Purpose – This study is intended to investigate the current practices and problems in heavy equipment management as well as to identify practices capable of alleviating equipment management problems for highway contractors in Thailand.
Design/methodology/approach – Equipment management practices were identified and analysed by SPSS using a questionnaire survey. ANOVA test was used to reveal significant differences in equipment management practices among different contractor sizes. Relationships between equipment management practices and problems were also revealed.
Findings – The equipment management practices vary, to some extent, among different contractor sizes. While practices of medium and small contractors tend to be similar, practices of large contractors are different from those of smaller contractors. Large contractors often put more emphasis on outsourcing strategy for equipment management. Moreover, large contractors frequently dispose of or replace equipment as soon as the equipment becomes inefficient before incurring high repair costs. Conversely, smaller contractors tend to mainly emphasis on the company finance and the budget availability as they often rely on purchasing strategy, especially buying used machines. Overall, equipment practices of large contractors were found to be more successful than smaller contractors in minimising equipment management problems, including long downtime duration and cost.
Originality/value – This research is of value for better understanding practices and problems relating to heavy equipment management among different contractor sizes. The study also highlights practices that are capable of reducing problems relating to heavy equipment management for highway contractors.
Keywords Construction equipment, Construction industry, Thailand
Paper type Research paper

MPM2 HCM - Final Project Study Presentation Examination

Mr Hoang Ngoc Anh made a presentation on "New Urban Zone Infrastructure Development Project Risks - A Case Study of An Phu Tay Residential Project"

Mr Hoang Don Dung made a presentation on "Quality and Safety Management for Construction Temporary Support Structures With Reference of Regulation and Contract in Vietnam"

Ms. Thanh Truc Nguyen Thi made a presentation on "Claim Management and Analysis"

Mr Bui Giang Nam made a presenation on "Safety Management System for Steel Fabrication and Construction"

from left to right: Dr Greg Chiu, Dr Hadikusumo and Dr Chotchai are examining Professional Master Students' Final Project Study.

Dr Chotchai, Dr Hadikusumo, Dr Greg Chiu and Dr Huynh Truong Luong came to Ho Chi Minh City on 28-29 November 2009 to examine 21 profesional master students in project management in construction.

1. Nguyen Canh Toan
2. Nguyen Huynh Trung Hai
3. Bui Van Cuong
4. Le Khac Bao
5. Phan Hong Hoan
6. Hoang Ngoc Anh
7. Hoang Dong Dung
8. Bui Giang Nam
9. Nguyen Thi Thanh Truc
10. Nguyen Hoang Anh Chuong
11. Tran Hong Quan
12. Le Hoai Viet
13. Nguyen An Khe
14. Nguyen Anh Kiet
15. Phan Vu
16. Nguyen Phong
17. Pham Thi Ngoc Hien
18. Tran Thi Nguyen Cat
19 Huynh Nhat Thong
20. Nguyen Huu Phuc
21. Nguyen Duc Hung

Measuring effectiveness of safety programmes in the Thai construction industry

THANET AKSORN* and BONAVENTURA H. W. HADIKUSUMO

Introduction

In Thailand, the construction industry has been experiencing an expansive and increasing volume of market demand in accordance with the high economic growth of the country following its recovery from the financial crisis in 1997. The aftermath of this development has however had an adverse impact on the wellbeing of workers as evidenced by poor safety records at construction sites. This relatively high and stable economic growth in Thailand has led to a rapid increase in construction work and consequently an influx of unskilled workers to the major cities. Most workers currently hired in the construction industry are originally from the agricultural areas and provinces, with a low level of education and skills. In addition to the temporary nature of both construction and agricultural work, many of these workers engage themselves seasonally and tend to split their time between agricultural production and construction works. Such factors therefore make it difficult for the construction industry to maintain high safety standards. According to the Social Security Statistics of Thailand (2004 cited in ILO, 2005), the construction industry has the highest rate of deaths, accounting for close to 100 workers per year. In addition, up to 20 000 workers have suffered minor injuries on jobsites every year. Therefore, there has been a growing awareness within the government and private sectors towards improving construction site safety in order to provide better protection and safety to workers. In order to reduce the unacceptable statistics of accidents and injuries in the Thai construction industry, the Ministry of Labour and Social Welfare launched a basic safety management framework at the enterprise level wherein the implementation of safety programmes was promoted. Given that the personal safety and health of each employee is of primary concern, the prevention of occupational accidents and injuries is of such consequence that it will be given precedence over operational productivity. On the other hand, according to Siriruttanapruk and Anantagulnathi (2004), improving construction site safety formidable problem due to limited resources available to governmental and non-governmental safety institutions to carry out inspections and to give advice and guidance for implementing safety programmes effectively. From a global perspective, to assist the construction industry in improving its safety performance, several studies (Tam and Fung, 1998; Sawacha et al., 1999; Poon et al., 2000; and Hinze and Gambatese, 2003) have been conducted to identify appropriate safety strategies on jobsites. Research has shown that the development and implementation of an effective safety programme can reduce site accidents (Liska et al., 1993; Findley et al., 2004). However, it is unclear which policies are the most effective programmes in achieving improved safety performance.

A closer look at the methodologies used in the previous studies reveals that effectiveness is commonly measured by correlating the safety programmes with reactive safety indicators (i.e. lost time injury rates, frequency and severity rates, fatalities, first aid cases). However, there are very few studies which measure the effectiveness of safety programmes by using proactive indicators of safety performance. The proactive approach is considered a new measurement paradigm, which can be used to assess the current state of safety level, for example, workers’ attitudes (i.e. unsafe acts) and working conditions (i.e. unsafe conditions). The proactive approach can identify such factors that can contribute to future accidents and meaningfully provide the necessary feedback to management to provide more appropriate preventive measures (Cantarella, 1998; Mohamed, 2003).

In response to the consistently poor safety performance of the construction industry, this study was conducted with construction projects in Thailand and aimed at identifying safety programmes that are clearly proven to be effective in reducing accidents (reactive safety performance indicators) and decreasing unsafe acts and unsafe working conditions (proactive safety performance indicators). The results of the study provide management with practical guidelines for implementing safety programmes more effectively.

Literature review

Several researchers have proved that there is a strong positive association between safety programme implementation and improved safety performance. For example, Jaselskis et al. (1996) investigated strategies for achieving better construction safety performance and established several important factors such as project manager experience and level, supportive upper management attitude, time devoted to safety for project safety representatives, safety meetings, frequency of site inspections and budget allocation for safety awards. Tam and Fung (1998) conducted a quantitative study to investigate relationships between safety practices and safety performance on construction sites in Hong Kong and revealed that improved site safety was associated with involvement of top management, safety orientation for new workers, safety awards or incentive schemes, use of post-accident investigation, safety training, safety committees and level of subcontracting. Similarly, Sawacha et al. (1999) uncovered that a safety programme that has the most effect on site safety consists of management talks on safety, provision of safety booklets, provision of safety equipment, providing a safe environment and appointing a trained safety representative on site.

Poon et al. (2000) recommended that post-accident investigation is the most effective task for reducing site accidents. They concluded that accident investigation can trace the causes of accidents and as such, appropriate preventive measures can be taken accordingly. Findley et al. (2004) proved that the employment of full-time safety managers and presentation of pre-job safety briefs are the key elements of superior safety performance. Their studies pointed out that safety functions cannot be run smoothly without appointment of onsite full-time safety managers who can provide the required and necessary leadership to facilitate preventive and corrective guidance.

In conclusion, these previous studies provide a useful guideline on the subject of construction site safety. The authors summarized the key elements of an effective safety programme based on previous research (e.g. Tam and Fung, 1998; Poon et al., 2000; Goldenhar et al., 2001; Hinze and Gambatese, 2003; and Findley et al., 2004). These studies were conducted to evaluate the influence of safety programmes on improved construction safety performance and revealed that successful safety programmes, however, do not need extensive elements, but should at least include the critical elements including safety policy, safety committees, safety inductions, safety training, safety inspections, accident investigations, first aid programmes, in-house safety rules, safety incentives, control of subcontractors, selection of employees, personal protection programmes, emergency preparedness planning, safety-related promotions, safety auditing, safety record keeping and job hazard analysis. These safety programmes were used as research variables in this study.

Defining safety programme effectiveness

Prior to elaborating on this research on construction safety programmes, it is essential to understand what is meant by the term ‘safety programme effectiveness’. Wojtczak (2002) defined effectiveness as a measure of the extent to which a specific intervention, procedure or service, when deployed in routine circumstances, does what it is intended to do. Erlendsson (2002) defined effectiveness as the extent to which objectives are achieved or ‘doing the right things’. Furthermore, Collins (2005) offered a rather helpful explanation by declaring that managers typically either ‘do things right’ or ‘do the right things’. Doing things right means efficiency, which refers to getting the best output from available resources. Doing the right things means effectiveness, which refers to setting the right goals and objectives and then ensuring they are accomplished. In this study, the effectiveness of safety programmes is defined as the extent to which the implemented safety programmes achieve the intended outcomes. The outcomes were expected to be highly related to improved construction safety performance including the reduction of work-related accidents, unsafe practices and unsafe working conditions.

Conclusions

The effectiveness of safety programmes in improving safety performance on construction sites in Thailand was investigated. More specifically, the relationship between the actual status of safety programmes and associated safety performance was examined. The results show that, overall, large-scale construction projects have better safety performance than medium scale projects, as evidenced by having fewer accidents, unsafe acts and unsafe conditions.

Furthermore, the actual status of safety programmes implemented by participating projects was evaluated. It was found that five safety programmes, namely safety record keeping, safety inductions, control of subcontractors, safety committees and safety training, have very high average evaluation scores. Thus, it is implied that these five programmes are being given appropriate consideration by all construction projects to implement on jobsites.

A stepwise multiple regression technique was employed to create the models that explain the interrelated effects of safety programmes on safety performance. Consequently, three regression models were extracted from the analysis. First, four of the 17 safety programmes, namely accident investigations, safety inspections, control of subcontractors and safety incentives were found to be the most effective in improving accident rates at construction sites. Secondly, the five most effective safety programmes in minimizing the occurrence of unsafe acts at construction sites were safety inspections, accident investigations, job hazard analysis, safety committees and safety record keeping. And thirdly, accident investigations, safety inspections, job hazard analysis, safety inductions and safety auditing were identified as the five most effective factors in decreasing unsafe conditions at construction sites.

In the light of this study, construction managers can use these quantitative results to establish an effective safety programme for achieving improved construction site safety performance.

Abstract

Some safety programmes are more effective than others in improving safety performance at the project level. The effectiveness of safety programmes was evaluated by studying 70 construction projects in the Thai construction sector, examining the relationship between their actual status and associated site safety performance. The actual status was assessed by using an evaluation tool developed in compliance with Thai safety legislation and validated by safety experts. Safety performance was assessed by using reactive and proactive measures. Particularly, the accident rate was used as a reactive indicator, while the unsafe act index and the unsafe condition index were used as proactive indicators. The results demonstrated that safety performance was influenced by the nature of implemented safety programmes. First, safety programmes which positively affect accident rates include accident investigations, jobsite inspections, control of subcontractors and safety incentives. Secondly, five programmes, namely jobsite inspections, accident investigations, job hazard analysis, safety committees and safety record keeping, were found to have the most contributions to fewer unsafe acts. And thirdly, accident investigations, jobsite inspections, job hazard analysis, safety inductions and safety auditing were the most effective programmes in reducing unsafe conditions.

Keywords: Accident, safety, health and safety, performance improvement, Thailand.

*Author for correspondence. E-mail: artty_th@yahoo.com

To cite this Article Aksorn, Thanet and Hadikusumo, Bonaventura H. W.'Measuring effectiveness of safety programmes in the Thai construction industry', Construction Management and Economics, 26: 4, 409 — 421.

Full paper will be available upon request.

The Unsafe Acts and the Decision-to-Err Factors of Thai Construction Workers

*Thanet Aksorn and B.H.W. Hadikusumo

INTRODUCTION

In Thailand, many construction activities have been carried out to meet the high demands of the expansive market. However, the construction industry has faced a wide range of challenges, one of which is the high accident and injury rate at the project level. According to the accident rate in all industries recorded by Ministry of Labour (International Labour Organization, 2005), the rate of accidents and fatalities in Thai construction is reported as the highest. In 2003, the construction industry accounts for 14% of the total number of 787 deaths at work and 24% of the total 17 cases of permanent disability. Construction is a labor intensive industry, in which workers play a very important role in the success of the various projects undertaken. Thus, the need to protect workers from accidents becomes a major consideration in any construction organization. For many years, safety practitioners have addressed physical preventive measures such as machine guarding, housekeeping and inspection, since poor physical conditions are believed to cause accidents. However, not much preventive work has been done on the human aspects. The fact that many researchers are of the opinion that unsafe acts of workers are the major contributors of accidents and injuries, rather than poor working conditions (e.g., Sawacha et al., 1999; Abdelhamid and Everett, 2000; Stranks, 2000; Haupt, 2001; Holt, 2001; Goetsch, 2005), suggests that there is the need for a change of direction in construction safety research to identify the possible influential factors of workers' decisions.

Theoretically, there are two types of unsafe acts, which can be classified as either errors or violations (Reason, 1990). In the most accident databases, the errors are major contributor to accidents. Violations, on the other hand, are less common. Unsafe acts of workers may occur in two conditions. First, a worker does not know while he/she is acting unsafely and second, he/she knows while he/she is acting unsafely. The first case can be easily tackled by providing safety education to the worker, close supervision, good work system design, etc. However, the second case is more complex because the reasons for acting unsafely could be due to different factors, such as the worker's personality, the nature of the job being undertaken, the extent of managerial support and workgroup influence. The second case is known as "the worker's decision-to-err", in which, though a worker is fully aware that he/she is working unsafely, he/she still decides to carry on with such unsafe acts. Therefore, knowing the causes behind the decisions to act unsafely can enable construction projects to develop the appropriate strategies to improve working practices of workers. This is the purpose for which this research was conducted.

OBJECTIVE OF THE STUDY

This research is designed to investigate the relationship between the decision-to-err factors and the unsafe acts. This relationship is important for management to study what unsafe acts could occur on the site, to find out what decision-to-err factors might contribute to these unsafe acts and to develop solutions which could reduce such unsafe acts.

UNSAFE ACTS

Generally, accidents at work occur either due to unsafe working conditions and unsafe worker acts. In construction, it is suggested that unsafe act is the most significant factor in the cause of site accident (Sawacha et al., 1999; Abdelhamid and Everett, 2000). There is no general agreement on definition of an unsafe act. However, it has been defined in similar focus on unaccepted practices which have the potential for producing future accidents and injuries. For example, Stranks (2000) gave the definition of unsafe act as "…any act that deviates from generally recognized safe way of doing a job and increases the likelihood of an accident…". Several unsafe acts have been identified by many researchers such as Petersen (1984), Anton (1989), Stranks (1994), Simachokdee (1994), Michuad (1995), Abdelhamid and Everett (2000), and Holt (2001).

These unsafe acts are:

• Working without authority on the job can cause accidents since unauthorized workers may lack the necessary skills, or unfamiliar with the job process.

• Failure to warn or to secure members out of danger is considered as an unsafe act since many accidents occur because workers pay less attention to warning or securing co-workers who are working under conditions with high probability of accident occurrence.

• Working at improper speeds, exceeding the prescribed speed limits, or unsafe speed actions could cause accidents, e.g. workers who handle objects quickly could slip and be injured.

• Improper lifting, handling, or moving of objects may cause serious back pains, e.g. workers who manually lift heavy objects without proper force-saving equipment.

• Improper placing and stacking of objects and materials in dangerous locations can result in unpredicted accidents e.g. a worker could collide with such objects.

• Incorrect use of tools and equipment, hand tools, power tools, and machinery can also cause accidents. For instance, workers who frequently climb or stand on rebars instead of using a ladder could fall down.

• Using defective equipment and tools to work, e.g. a worker who uses a substandard ladder could fall and be injured.

• Annoyance and horseplay in the workplace such as young workers who play roughly around the workplace could encounter unexpected accidents.

• Ignoring to wear personal protective equipment (PPE) may increase chances of getting injured, e.g. workers without hardhats are more prone to getting head injuries from falling objects.

• Removing safety guards from the workplace or equipment could raise the chances of getting accidents, e.g. workers who remove guardrails could fall down.

• Smoking, creating naked flame or sparks in areas where flammable materials are stored could cause explosions.

• Leaving nails or other sharp objects protruding from timber may cause accidents as workers who do not wear safety shoes could step on these objects and be injured.

• Throwing or accidentally dropping objects from high levels could expose other workers to sustaining possible head injury.

• Working under the effects of alcohol and other drugs could increase workers' unawareness and cause serious accidents.

• Improper positioning of tasks can also result in accidents, e.g., workers on high levels could fall and be seriously injured.

• Improper posture for tasks such as workers taking shortcuts by climbing or jumping from high levels instead of using ladders could result in serious injury.

• Servicing equipment which is in operation, e.g. refueling a machine without first turning off the engine could cause a severe accident.

• Working with lack of concentration, such as workers talking while undertaking a job could cause distraction and result in an accident.

• Working in poor physical conditions such fatigue, stress, or drowsiness could also increase the likelihood of accidents.

DECISIONS-TO-ERR IN OCCUPATIONAL SAFETY

The decision-to-err can contribute to human errors which could subsequently lead to the occurrence of accidents (Wiegmann et al., 2005). On the other hand, human errors could stem from the decisions made by workers (LaDou, 1994). For instance, if a supervisor pressures a worker to increase the rate of production, the worker might choose an unsafe approach rather than a safe one in order to save time and get the job done as quickly as possible. Petersen (1984) proposed a causation model which explains that the decisions of workers to err are due to three main causes:

1. Logical decisions in different situations such as peer pressure, close supervision, management priorities, and personal value system.

2. Unconscious decisions-to-err, which includes proneness and mental problems.

3. Perceived low probability in which the workers believe that they will not have an accident.

Decision-to-err factors were gathered from literature review and interview with 20 Thai construction workers. Twenty factors were identified and grouped under four categories: personal, job, management and workgroup.

PERSONAL FACTORS

Laziness

Hall (1995) stated that most workers prefer to take shortcuts to save time because they want to avoid supportive activities. Workers oftentimes prefer to work with the wrong tools because they feel that it is too much trouble getting the right one, e.g. workers could climb or stand on rebars (an inadequate working platform) instead of using a proper ladder.

Past Experience

Some workers, having performed a job in a familiar way for many years are very reluctant to give up their old way of doing things. However, these old habits could prevent them from noticing the prevailing hazards, thereby increasing the possibility of accidents occurrence (Kittleson, 1995).

Being in a Hurry

Stice (1995) stated that pressure from supervisors to get jobs done quickly can cause the workers to work in hurry. As a result of such pressures, workers may disregard good safety practices to save time for completing the jobs.

Showing Off

"Watch me" is usually heard from workers who like to display their manhood in order to gain the admiration of their colleagues. Kittleson (1995) stated that some "macho" types of workers like to show off their capability to their peer improperly. This "show-off" behavior can, and often does, results in accidents.

Being Angry

Kittleson (1995) mentioned that being angry can lead to accidents because anger nearly always rules over caution. When someone gets angry, he or she will start to sweat, tremble, get knots in the stomach, or grind his/her teeth. Unresolved anger could cause distraction, proneness to accidents, anxiety, violence and rage.

Being Uncomfortable

The International Labour Organization (ILO, undated) revealed that PPE can be uncomfortable, can decrease work performance and can create new health and safety hazards. Some workers for instance, reject the wearing of earmuff because it makes them feel hot, especially when it is used in hot regions.

Effects of Using Drugs and Alcohol

Michuad (1995) stated that workers who use drugs and alcohol have the tendency to distort or block their decision-making capability. In general, experimental research has shown that alcohol has a delirious effect on performance due to its effects on judgment, reasoning and memory. Drugs users and drinkers often experience reduced levels unawareness, a situation which could lead to decision errors and unsafe working. When the influence of the drug or alcohol is over, a worker might wonder why he did the unsafe act.

Supervisor's and Co-workers' Acceptance

In order to gain the acceptance of supervisors or coworkers, a worker could choose to perform a job unsafely. For example, a worker could decide to unload some materials faster so as to save time for completing the job and thereby gain the acceptance, approval or the admiration of his/her supervisor or co-workers.

Overconfidence

Confidence is a good thing, but overconfidence would oftentimes do more harm than good. "It will never happen to me" attitude could lead to improper procedures or methods that could cause injury (Hirsch, 1998).

JOB FACTORS

Stress has been defined as human's reaction against a threatening situation (Goetsch, 2005). Schermerhorn (2001) further defined stress as "the state of tension experienced by individuals who are facing extraordinary demands, constraints, or opportunities." Some potential factors that could contribute to job stress in the construction industry are:

Too Much Work (Work Overload)

Asking workers to do more than they could handle may result in the workers developing high stress, especially when deadline pressures are put on them. According to Greenberg and Baron (2000), there are two different forms of work overload: quantitative overload, which occurs when individuals are asked to do more and qualitative overload, which refers to employees' belief that they lack of the required skills or abilities to perform the work.

Too Little Work (Work Underload)

Similarly, being asked to do too little could also be as stressful as being asked to do too much. Greenberg and Baron (2000) proposed that there are two types of work underload: quantitative underload, which refers to the boredom arising from having too little work to do, and qualitative underload, which is the lack of mental stimulation, such as routines, and repetitive jobs.

Time Pressure

When workers are unable to meet deadlines, they instantly get overwhelmed and begin to worry (Timm and Peterson, 1986; Stranks, 2000). In addition, when the work process is changed and the workers are not given enough time to complete the job, they easily become stressed.

MANAGEMENT FACTORS

Management Pressure

Stranks (1994) stated that supervisors who are in charge of low-producing units normally tend to spend more time with their subordinates. These supervisors usually divide job times into many short periods to give specific instructions such as, "do this", "do that", or "do it this way", to their subordinates, hoping to increase productivity. However, supervisors' pressure may cause subordinates to work unsafely while trying to satisfy the supervisors' objectives, such as completing the work within unreasonable time schedule.

Management Support

Hammer and Price (2001) proposed that in order to ensure construction site safety, management should fully support and ensure that safety devices and temporary structures are in good conditions, allocate sufficient budgets for establishing safe works, and establish an effective program to monitor and audit operational activities for their safety.

Supervision

LaDou (1994) stated that it is very obvious that any successful safety program must necessary involve the supervisors. Supervisors should closely control all the workers activities. If supervisors could convince workers that safety has to be considered all the time, then the workers will do everything to prevent accidents.

Reward and Penalty

Motivational factors from the management could have negative impact on inspiring workers to work safely as inappropriate ways of giving rewards and penalties could motivate workers to work unsafely. For example, a worker may decide to work unsafely because he/she thinks that doing this can speed up the work, which would mean getting more reward such as bonus. Penalty could also motivate workers to work unsafely, e.g. a worker who is physically unfit could force himself/herself to go to work, out of the fear of being penalized.

WORKGROUP FACTORS

Group Norms

Each employee is not just an individual, but a member of a group as well (Stranks, 1994; Gibson et al., 2000). Each group has its own norms, sets its own work goals, moral standards, and makes its own decisions. The norms also incorporate the behavior of workers towards their boss, and how workers react towards safety regulations. Kittleson (1995) stated that it is easier for the workers to base their behavior on others than to do the right thing. For example, a worker may hear, "everyone else does it that way" and therefore follow the group in working in a similar way even though it is an unsafe method.

Group Pressure

Ellis and Fisher (1994) stated that certain groups pressure their members to conform to their established norms, otherwise, erring members will be penalized.

CONCLUSIONS

The unsafe acts practices and the decision-to-err factors influencing workers' unsafe acts on construction sites in Thailand were explored in this study. Nevertheless, there are some limitations of the study need to be elucidated. It should be noted that the ranking of frequencies of unsafe acts was obtained from the workers' recall. The frequencies did not come from actual field observation; therefore, the ranking does not necessarily correspond to the current situation of unsafe acts. Additionally, a number of unsafe acts were limited to the workers since a list already provided by the authors. The results revealed that the most frequent unsafe acts committed by construction workers are: (1) the workers rarely wear PPE while doing their jobs; (2) the workers lift or handle objects or materials improperly; and (3) the workers leave nails and other sharp objects in dangerous locations.

Our study also indicated that there are some relationships between the workers' characteristics (i.e., age, occupation and experience) and the unsafe acts. The four subgroups of workers classified by age are different in making annoyance and horseplay in the workplace. The young workers tend to commit this unsafe act more often than the older group. The four subgroups of workers classified by their experience differ in wearing PPE, leaving nails or sharp objects in dangerous locations, and working in dangerous positions. Inexperienced workers tend to ignore wearing PPE, and work in dangerous positions rather than the experienced ones, whereas, experienced workers tend to be more frequent in leaving nails or other sharp objects in dangerous locations. Moreover, the five subgroups of workers classified by their job occupation are different in seven types of unsafe acts. The results indicated that carpenters are more often in working without authority and skills, and in leaving nails or sharp objects in dangerous locations. Masons tend to be more in improper lifting, handling and moving materials, and in throwing and dropping materials from high levels compared to others.
Furthermore, steel workers tend to be more in making annoyance and horseplay, and removing safety guards; while, unskilled workers tend to be more in ignoring to wear PPE at the workplace.

In order to explain why the unsafe acts happen, the decision-to-err factors were also explored. It was determined that there are many potential decision-to-err factors causing unsafe acts, the stepwise multiple regression analysis was then employed to remove insignificant factors. The most frequent unsafe acts rated by more than 30 respondents were selected. The minimum of 30 respondents is the requirement for parametric test of statistical analysis. The first unsafe act, rated by 140 workers, was the failure to wear PPE. This unsafe act was statistically correlated with five factors: lack of management support, group norms, overconfidence, being uncomfortable, and past experience. The second unsafe act, rated by 58 workers, was improper lifting, handling and moving objects. This unsafe act was statistically associated with three main factors: group norms, overconfidence, and management pressure. The third unsafe act, rated by 34 workers, was leaving nails or other sharp objects in dangerous locations. This unsafe act was statistically associated with three main factors: group norms, laziness and overconfidence.

FURTHER RESEARCH

This study could be broadened to include a larger workforce sample to enhance the level of reliability of the research. This study can be more complete if the limitations of the study are overcome. It is suggested that the frequency of unsafe acts should be obtained from field observation. The results of observation will be most likely to represent actual state of unsafe acts that occur on sites. As a result of time constraint, this study could not obtain decision-to-err factors for all identified unsafe acts. If it is possible, more research should be carried out to investigate decision-to-err factors for all types of unsafe acts. As a result, managers can develop appropriate preventive measures to reduce the occurrences of those unsafe acts. Finally, it may be of interest to perform a boarder study to investigate the relationships between the occurrences of unsafe acts and site safety performance (e.g., accident rate). By doing this, the managers will know which types of unsafe practices have greater impact on safety performance.

This study was published in the “Journal of Construction in Developing Countries, Vol. 12, No. 1, 2007”. Full journal article is available upon request.

Abstract: The unsafe acts of workers are considered as major contributors of work-related accidents and injuries on construction sites. However, not much work has been done to address the reasons why unsafe acts of workers occur particularly in construction industry. The aim of this paper therefore, is to investigate the major unsafe acts (i.e., at-risk behavior), and the decision-to-err factors causing unsafe acts. A questionnaire survey was conducted to collect data from a total of 214 workers from 20 building construction projects in Thailand. The findings revealed that the failure of workers to wear personal protective equipment (PPE), improper lifting or handling of materials, and keeping sharp objects in dangerous locations, are the major unsafe acts which frequently occur on construction sites in Thailand. In addition, the paper reported that the top three most frequent unsafe acts are statistically associated with several decision-to-err factors, including lack of management support, management pressure, group norms, overconfidence, being uncomfortable, past experience and laziness.

Keywords: Accident, Construction, Decision-to-err, Human factor, Safety, Unsafe behavior.

Construction Engineering and Infrastructure Management, School of Civil
Engineering, Asian Institute of Technology, Pathumthani, THAILAND.
*Corresponding author: artty_th@yahoo.com

Safety Management Practices in the Bhutanese Construction Industry

Kin Dorji1 and *Bonaventura H. W. Hadikusumo2

INTRODUCTION

It is commonly known that accidents have serious implications to the construction industry both in financial and humanitarian terms. Construction accidents may cause many problems, such as demotivation of workers; disruption of site activities; delay of project progress; and adversely affecting the overall cost, productivity and reputation of the construction industry (Mohamed, 1999). In Hong Kong, the cost of accidents accounts 8.5% of the total tender price (Rowlinson, 2003).

Considering the adverse impacts of accidents, construction safety management is of genuine concern to all stakeholders in the construction industry. Government, unions and insurers have spent a great deal of time and effort attempting to evolve legislation, rules and regulations to help reduce the large loss of life and limbs, and the high number of "lost-work days" (Goldsmith, 1987). In USA, the practice of safety in construction is regulated by governmental agencies such as the Occupational Safety and Health Administration (OSHA), which provides strict rules and regulations to enforce safety and health reduce accident rates unless craftsmen and management take positive actions to integrate these rules into their everyday activities by implementing a safety management program. Safety management is an approach aimed at removing or minimizing the forces which cause losses through injured workers, or damaged equipment and facilities.

In most developing countries, including Bhutan, safety consideration in construction project delivery is not given a priority, and employment of safety measures during construction is considered a burden (Mbuya and Lema, 2002). The construction industry in Bhutan is one of the fastest growing and largest sectors. It is also one of the highest contributing sectors to the national gross domestic product (GDP) next to agriculture. However, occupational safety and health in the construction industry in Bhutan is at the very basic level. It lacks all of the three fronts of engineering, education and enforcement ("Three E's) of safety. Safety concerns have been raised, of late, and earnest efforts are being made to promote safety and health in the Bhutanese construction industry. The industry, as such, needs to assess the safety situation, and accordingly plan and implement safe construction in Bhutan. Currently there is a genuine set of data on safety at construction sites in Bhutan. Apparently, there are no systematic and organized studies conducted specifically on the safety aspects of the construction industry in Bhutan. Therefore, this research study was aimed to assess the existing safety management practices and perception in the Bhutanese construction industry. The assessment was useful in providing information in terms of current safety practices administered in Bhutan. Meanwhile the perception was useful in finding out what are the main reasons, and whether the regulator and construction companies have different perceptions in identifying problems related to safety management. If they perceive different opinions on safety problems, the safety policy and law might not be able to solve the problems. The health issues are not covered in this study because the impact of health is long term; and at present the data is not available in the Bhutanese construction industry.

BHUTANESE CONSTRUCTION INDUSTRY AND GOVERNMENT ROLES IN SAFETY

The construction industry is one of the fastest growing and largest employing industries in Bhutan. It is also, like in any other developing countries, one of the major stakeholders of the national economy. Its contribution to the national GDP rose from 6.7% in the early 1990s to about 12% in 2002. The construction industry, however, is dominated by the government since most of the major infrastructure developmental works are owned by the government.

During the Eighth Five Year Plan (8 FYP) (1997–2002) the construction sector, with an estimated growth rate of 17.3%, had a major influence on the GDP growth rate mainly because of the construction of large hydropower projects. The Ninth Plan (2002–2007) has placed much emphasis upon the infrastructure development such as urban housing projects; and because of this, construction sector has been projected to grow at an average of around 16.4% per annum. The construction sector is also expected to contribute 17.8% to the national GDP at the end of the Ninth Plan.

In order to support the construction development, technological and managerial aspects of the Bhutanese contractors must be improved. Many new government agencies have been created in response to these needs. Some of them are Standard and Quality Control Authority (SQCA), Construction Association of Bhutan (CAB), Construction Training Centre (CTC), Department of Labour (DOL) and others. The role of the CAB is to represent as a forum for the construction industry, and to address problems and policy issues at national, regional and international level for the development and promotion of Bhutanese construction industry. SQCA is currently one of the main government regulatory agencies entrusted with the tasks of regulating the quality aspects of the construction works in the country. In the past, the former Public Works Department (PWD) used to be the only central agency entrusted with all the engineering works of the government. However, over time, with increasing volume of works it has been proliferated to several other government agencies. As such, today, every Royal government agency possesses a small team of engineers to oversee its engineering functions. This over stretch has resulted in the variations in the construction and engineering standards.

The Ministry of Works and Human Settlement takes its roles in overseeing the construction industry in Bhutan. The Ministry carries out most of the developments and implementation of various rules and regulations, policies, bye-laws and standards, etc. that has general bearing on the construction industry. However, there is no single specific government agency that regulates the construction safety. There is no concrete legislative standard either for construction safety and health. The only legal instrument protecting the working conditions of national and foreign workers is the Chathrim for Wage, Recruitment Agencies and Workmen's Compensation 1994 passed by the National Assembly and implemented by the Ministry of Home Affairs. Even the applicability of this labour regulations is limited to the five categories of workers (designated by skill levels) identified in the Chathrim. The Chathrim and its related amendments also establish the minimum wage levels and welfare such as accident insurance coverage, medical coverage and safe working conditions.

The Ministry of Labour and Human Resources which has been recently established in June 2003 has been entrusted with the responsibility for labour administration policies and laws. The occupational safety and health related laws and regulations are currently encompassed in the overall labour administration policy and law, which are still at the draft stage. The DOL under the same Ministry is mandated to assume responsibility for labour inspection and labour relations functions. Over the next few years, the DOL will be striving to achieve the following objectives in terms of safety and health management (MLHR, 2004):

a. Labour laws and regulations concerning labour inspection and labour relations will be drafted, submitted to the national assembly, enacted, widely publicized and enforced.

b. All workers, both national and foreign, will benefit from labour protection activities through a safer and healthier working environment, and improved working conditions.

c. A national occupational safety and health policy will be in place, and supporting laws and regulations will be enacted, implemented and enforced.

d. An integrated labour inspection system will be established and become operational.

e. A system for bargaining by the Department on behalf of the employees on a range of labour relations issues, including wages and working conditions, will be established until the finalization of the nation's constitution.

SAFETY MANAGEMENT SYSTEM

Management approach to health and safety in construction industry can be seen in three important ways – firstly, from legal point of view, the need to abide the rules and regulations of the place; second, the socio-humanitarian aspects which is to consider human lives involved; and finally, the financial-economic aspects of the accidents which have high direct and indirect costs.
Construction safety management deals with actions that managers at all levels can take to create an organizational setting in which workers will be trained and motivated to perform safe and productive construction work (Levitt and Samelson, 1987). The system should delineate responsibilities and accountabilities. It should also outline procedures for eliminating hazards and identifying potential hazards before they become the contributing factors to unfortunate accidents.

Safety Policy

A health and safety policy is a written statement of principles and goals embodying the company's commitment to workplace health and safety (CSAO, 1993). It demonstrates top management's commitment to ensure safe working methods and environment at the construction sites. Koehn et al. (1995) states that in order to reduce financial risk, management support for safety programmes in both developed and developing countries should be considered as an economic necessity since accidents had proved quite costly to the contractor. This is in addition to the ethical and professional responsibility of the management for providing a safe work site for all employees. Sawacha et al. (1999) also stresses the importance of management's viability and participation in achieving successful safety performance. The safety policy elements which are applicable in Bhutan are written safety policy, proper posting of policy, effective implementation and policy updating.

Organizing

One of the essential elements of the safety management is the designation of individual with responsibilities and accountabilities in the implementation of the construction safety programme and plan. The organization should demonstrate how accountabilities are fixed, how policy implementation is to be monitored, how safety committees and safety representatives are to function, and how individual job descriptions should reflect health and safety responsibilities and associated accountabilities (Stranks, 2000). As such, in order for the safety policy to be effective, both management and employees have to be actively involved and committed (Holt, 2001). In the research finding of Sawacha et al. (1999), it indicates that having a well-trained safety representative on site can improve safety performance by undertaking fault spotting and insisting on corrective action being taken. Also having full-time safety personnel will somewhat relieves the pressure on the on-site construction project team (Koehn et al. 1995). Sawacha et al. (1999) further indicates that companies with effective safety committees are more likely to take steps that improve safety performance than those without. This means that safety committees can play a positive role in the improvement of safety performance. In UK, the Safety Representatives and Safety Committees Regulations 1977 which was implemented by the HSC, describes the appointment and functions of safety representatives and the establishment of safety committees (Davies and Tomasin, 1996). Similarly, in USA the OSHA standards for the construction industry had listed the necessary requirements for a minimum standard of safety and health (Koehn et al. 1995). The committee is empowered to research, discuss, coordinate and make suggestions related to labour safety affairs at the job site. Organizing elements which are applicable to Bhutan are safety representative, safety committee, safety responsibilities and accountabilities, and organizational commitment (i.e. resources).

Planning and Implementing

Planning is a critical area in the control and enforcement of a safety program (Goldsmith, 1987). It is a process that prepares, creates, implements and monitors the safety programme, thereby addressing the workplace health and safety through an organized, step-by-step strategy (CSAO, 1993). Planning starts with the company's written health and safety policy. It ensures that health and safety efforts of all job-site personnel really work by designing a programme that translates policy into practice. Planning, as such, entails identifying the objectives and targets which are attainable and relevant, setting performance standards for management, considering and controlling risks to all employees and to other people who may be affected by the organization's activities, and ensuring documentation of all performance standards (Holt, 2001). The safety and health programme covers a range of general safety procedures and practices. Some of them are safety training, safety meeting, safety inspection, accident investigation and reporting, job hazard analysis and control, safety promotion, and personal protective equipment (PPE), etc.
The elements of planning and implementing safety programme which are applicable to Bhutan are safety plan, safety programme, safety training, safety inspection, job-site hazard identification and control, safety meeting, accident investigation and reporting, safety promotion and PPE.

Measuring Safety Performances

Safety performance measures are used primarily for comparisons among companies and supervisors. In addition, they are also used as a means for pinpointing problem areas (Levitt and Samelson, 1987). Also according to Laufer and Ledbetter (1986), a key factor in the control and improvement of any performance aspect on site is the ability to measure the performances. Measuring safety performances is important to check the effectiveness of various training methods and it also serves as an instrument in choosing a contractor. There are various methods of measuring the safety performances. Some of the common methods are experience modification rating (EMR), accident costs, frequency rate, behaviour-based safety and OSHA-recordable incidence rates. The elements of safety performance measurement which are applicable to Bhutan are accident cost and accident frequency rate.

Reviewing Safety Performances

The review of safety performances serves as a feedback loop to improve the performances. Safety audit can be undertaken to review the safety performance in terms of whether the safety plan is implemented and whether the plan is effective to attain the organization's safety goal.

CONCLUSION

A survey has been conducted with 40 construction companies and the government regulatory agencies relevant to construction industry in Bhutan to better understand their safety management practices. The five key elements of a construction safety management system were inadequately applied in the Bhutanese construction industry. In terms of safety policy, most of the companies did not have safety policy and they had poor safety awareness. In terms of organizing, most of them did not have safety department, safety representative and safety committee. Less than 25% of them did not have safety budget. In terms of planning and implementation, most of them were aware of the safety regulation and claimed to have insurance schemes for the workers depending on the clients' requirements. Most of them also claimed that they provided PPE to workers although some of the workers did not want to use the PPE because they felt uncomfortable. However, most of the companies did not have a formal safety plan. In terms of measuring and reviewing safety performance, many of the companies did not have proper records to give indication on the number of any kind of accidents occurring at their construction project sites. In addition, many did not employ safety audits.
Our study also concludes main reasons for why the application of safety management system was not adequate. The contractors perceive that the five top most reasons were (1) lack of safety training facilities, (2) lack of safety awareness and understanding of safety benefits, (3) lack of safety professionals, (4) lack of knowledge about safety management, and (5) lack of safety regulation enforcement. While the government officials perceived that financial constraint was one of the most important reasons instead of lack of safety professionals. The data showed that basically the contractors and government officials were not statistically different in their opinions.

This study was published in the “This Journal of Construction in Developing Countries, Vol. 11, No. 2, 2006” and full journal article is available upon request.

Abstract: The construction industry is considered as one of the most hazardous industrial sectors wherein the construction workers are more prone to accidents. In developed countries such as United Kingdom and United States of America, there is strict legal enforcement of safety in the construction industry and also in the implementation of safety management systems which are designed to minimize or eliminate accidents at work places. However, occupational safety in construction industry is very poor in developing countries such as Bhutan. This study investigates the prevalent safety management practices and perceptions in the construction industry in Bhutan. The study was conducted among 40 construction contractors and 14 government officials through method of questionnaire survey, interview and discussion. The results of the study revealed that there are many occupational safety problems in the construction industry in Bhutan, problems such as lack of safety regulations and standards, low priority of safety, lack of data on safety at construction sites, lack of competent manpower, lack of safety training, lack of safety promotion, and lack of documented and organized safety management systems. Furthermore, the study also proposes some recommendations for safe construction in Bhutan.

1Standards and Quality Control Authority, Ministry of Works and Human Settlement, ROYAL GOVERNMENT OF BHUTAN

2Construction Engineering and Insfrastructure Management, Asian Institute of Technology, Pathumthani, THAILAND. *Corresponding author: kusumo@ait.ac.th

Capturing Safety Knowledge Using Design-for-Safety-Process Tool

B. H. W. Hadikusumo1 and Steve Rowlinson2

Introduction

Construction site safety is of great importance to construction companies. Failure in managing construction safety results in worker injuries and impacts on financial losses, human conflicts, and civil penalties.

In order to provide a safe working environment for workers, governments set regulations. There are two kinds of safety regulations: prescribed safety regulations, where the government states minimal working conditions that must be provided in a construction site; and self-regulatory, where the government states general duties for an employer, thus allowing them to determine the best way of achieving the objectives of the legislation in an approach best suited to their organization.

For both systems, knowledge (i.e., experience) of a safety engineer is of great importance. In the prescribed system, it is a fact that governments could not state all of safety hazards that might be occurring at construction sites. In other words, the regulations do not reflect the dynamic nature of the construction processes; and therefore experience of safety engineers is very important. In the self-regulatory system, it is clear that an organization must develop its own approach to provide adequate working conditions and therefore the experience of safety engineers is equally of great importance.

This paper discusses an innovative method to capture the knowledge of safety engineers in terms of experience in safety hazards at construction sites and accident precautions by using a design-for-safety-process (DFSP) tool. First, knowledge management in construction site safety perspectives is discussed, and then the concept of DFSP tool and its function to capture the knowledge is presented. Finally, test cases to show the potential of the tool to capture the knowledge are reported.

Knowledge Management in Construction Site Safety Perspectives

Knowledge management (KM) has a lot of definitions; Hibbard (cited in Beckman 1999) defines it as ‘‘... the process of capturing a company’s collective expertise wherever it resides—in databases, on paper, or in people’s heads—and distributing it to wherever it can help produce the biggest payoff.’’ Beckman (1999) noted, ‘‘In order to transform knowledge into a valuable organizational asset, knowledge, experience, and expertise must be formalized, distributed, shared, and applied.’’ For this purpose, several authors proposed models for the KM process.

Beckman (cited in Beckman 1999) proposes eight stages of the KM process: (1) identifying, determining core competencies, sourcing strategy, and knowledge domain; (2) capturing, formalizing existing knowledge; (3) selecting, assessing knowledge relevance, value, and accuracy; (4) storing, representing corporate memory in knowledge repository with various knowledge schema; (5) sharing, distributing knowledge automatically to users based on interest and work; (6) applying, retrieving and using knowledge in making decisions, solving problems, automating or supporting work, job aids, and training; (7) creating, discovering new knowledge through research, experimenting, and creative thinking; and (8) selling, developing, and marketing new knowledge-based products and services.

In order to capture knowledge, it is very important to know typologies of knowledge. Several writers, such as Nonaka and Takeuchi (cited in Beckham 1999), Von Krogh et al (2000), and
Alter (2002), identify two types of knowledge typologies: explicit and tacit knowledge. Explicit knowledge is defined as knowledge which is precisely and formally articulated and is often codified in databases of corporate procedures and best practices, whereas tacit knowledge is understood and applied unconsciously (Alter 2002). Nonaka and Takeuchi (cited in Beckman 1999) differentiate these two typologies of knowledge in terms of experience–rational and practice–theory aspects. Tacit knowledge is knowledge of experience and it is related to practical aspects, while explicit knowledge is a knowledge of rationality and it is related to theoretical aspects.


Fig. 1. Frequency-consequences levels for categorizing safety hazards

Explicit Knowledge

The explicit knowledge of construction site safety exists in accident records, and safety regulations as well as safety guidelines. The accident records represent the knowledge of actual accidents reported on construction sites. This record is useful for the purpose of risk assessment for categorizing the safety hazards in terms of ‘‘frequency–consequence’’ level (see Fig. 1). By categorizing the hazards in terms of this frequency–consequence relationship, an organization can have better information regarding hazards which must be prioritized since it is not possible to allocate all of the organizational resources to respond to all the hazards which can occur. For example, in Fig. 1, hazards categorized as Type I must be prioritized while Type IV can be least considered. Type-I hazards may be hazards which may cause major consequences and often occur, such as falling objects from an unprotected opening in a slab in building construction projects. Type-II hazards may be hazards which may cause major consequences but seldom occur, such as a person falls from the upper floor of a building construction project, or minor consequences but often occur, such as a person gets caught by protruding rebars. Type-III hazards may be hazards which may cause moderate consequences and seldom occur, such as a person is struck by a tower crane. This categorization of hazards varies in different organizations since the frequency and consequences of accidents occurrence depend on several factors such as: (1) nature of the construction works, (2) quality and quantity of existing accident precautions used, and (3) safety culture.

Another type of explicit knowledge in site safety is safety regulations, such as Occupational Safety and Health Acts from the U.S. and Construction Site Safety Regulations (CSSR) of Hong Kong. The regulations state the minimum required conditions that must be met in a construction project; however these conditions are not enough to provide a safe working condition. This is especially true for contractors working in countries encouraging self-regulation through the implementation of a safety management system. This system provides general duties for an employer, thus allowing them to determine the best way of achieving the objectives of the legislation in an approach best suited to their organizational culture (Phillips 1998). In the self-regulatory system, tacit knowledge of construction site safety is of paramount importance for organizations since the knowledge of safety engineers and managers (i.e., experience knowledge) determines the quality of safe working conditions acceptable, and therefore their knowledge must be captured.

Tacit Knowledge

Von Krogh et al. (2000) noted that tacit knowledge is tied to the senses, skills in bodily movement, individual perception, physical experiences, rules of thumb, and intuition. In construction site safety, safety hazard recognition is an important actualization of tacit knowledge. Safety hazard recognition is considered a tacit knowledge because it relies on the safety engineer’s experience. A hazard is ‘‘a condition with the ‘potential’ of (causing) an accident or ill health’’ (King and Hudson 1985). This definition of a ‘hazard’ must be noted to avoid confusion with the definition of risk, which is the likelihood of an occurrence of a hazard (Phillips 1998).

Ramsey (cited in Furnham 1998) noted an important theory of hazard recognition, which in itself is an important element in the occurrence of an accident. If management does not recognize the hazards that may occur on a site, then management cannot provide relevant training or procedures to handle the uncertain conditions.

The importance of this theory is shown in a study of behavior-based safety management conducted by Lingard and Rowlinson (1997). The results of their study showed that behavior-based safety management successfully improved the safety performance with respect to personal protective equipment and housekeeping, but not bamboo scaffolding and access to heights. One reason for this was attributed to the failure of workers to recognize hazards.

In knowledge management, which is usually manifested in the form of a business system that is enabled by an array of technologies (Auditore 2002), both the explicit and tacit knowledge of construction site safety personnel must be captured to gain advantages including:
1. Establishment of an effective safety program which recognizes the actual safety hazards.
2. Establishment of an effective training program which improves workers’ skill related to the actual safety hazards identified.

Problems with Capturing Knowledge in Construction Site Safety

Explicit knowledge is easier to capture than tacit knowledge. Explicit knowledge related to construction site safety can be captured from existing theories and axioms written in books, regulations, company records, and guidelines. However, tacit knowledge exists from the experience of an individual (i.e., safety engineer or manager); therefore it is difficult to capture since the knowledge is stored in an unstructured manner in an individual’s mind.

There are two conventional mechanisms to capture the knowledge of safety engineers or managers. First, it can be undertaken by conducting discussions. For the purpose of representing cases for the discussion, several tools are required, such as engineering drawings, and method statements. The problems with these tools are the drawings and method statements are represented as texts and two-dimensional (2D) drawings which may be difficult to understand (Collier 1994), and the drawings only represent construction components, such as walls, beams, and columns; but they do not represent construction processes which also have inherent safety hazards (Young 1996). Second, it can also be undertaken by observing the actual site. This mechanism can provide better safety information related to the actual construction components and processes which may have safety hazards. An obvious advantage is that the actual representation of the components and processes can stimulate safety engineers or managers to recall the experience they have. However, this mechanism has some limitations: (1) it is unsafe to them since they are exposed to the construction operations; (2) it obstructs the workers in carrying out their works; and (3) it can only be undertaken during the construction stage.

Design-for-Safety-Process Tool for Capturing Construction Safety Knowledge

Due to the problems stated in the last section, a DFSP tool is proposed. In this research, this tool is designed for capturing safety knowledge in the Harmony Block of the Hong Kong Housing Authority (HKHA). This block design is built repetitively; and therefore, knowledge captured by using the DFSP tool can be reused in Harmony Block projects or in other similar construction projects.

The DFSP tool is developed based on three components: design for X-ability (DFX), virtual reality (VR), and construction site safety, as well as the safety hazard identification method. The advantage of using VR as a visualization tool is that it can enhance knowledge discovery (Auditore 2002). This is related to the nature of the human brain where it can process real- time, multidimensional data much more efficiently and faster than 2D data (Thierauf 1995). In the particular case of construction site safety, after design stage has been completed, construction components and processes of the Harmony Block construction project are represented in VR, called the virtually real construction project. By using this representation, safety engineers can observe the virtually real project and share their experience to identify safety hazards inherent within the virtually real project. In addition, they can also use their experience to propose suitable measures for the identified hazards.

Design for X-Ability

The fundamental concept of DFX is the ability to design a product from several viewpoints or characteristics (Gutwald cited in Prasad 1996). For example, one of the design-for-assembly approaches might be to investigate how a product design can be improved in terms of its assembly time as a performance measurement.

In order to develop a useful DFX tool, Huang (1996) noted five basic functionality requirements of a DFX tool. The five requirements are used as a DFX shell to develop the DFSP tool as follows: (1)gather and present facts; (2) measure performance; (3) evaluate whether or not a product/process design is good enough; (4) Compare design alternative; (5) highlight strengths and weaknesses.

In addition to the functionality requirements, Huang added another element: that the tool must stimulate creativity. Having this additional element, the DFX tool should encourage innovation and creativity, rather than impose restrictions. In the DFSP tool, there are sets of standards in the safety regulations that must be observed; for example, the minimum width of the working platform must be at least 400 mm if the working platform is not used to transport material. However, it does not restrict a user to creatively develop the best safety design solution. A user is provided with choices for establishing which accident precautions would be the most suitable, or to create a new design solution if it is considered better than the data available in the accident precautions.

This is the main reason why the DFSP tool, which is derived from DFX, can be used to capture construction site safety knowledge.

Virtual Reality

Aukstakalnis and Blatner (1992) define ‘‘VR as a way for humans to visualize, manipulate, and interact with computers and extremely complex data.’’ Burdea and Coiffet (1994) define VR in terms of its three important features that make it widely used by several industries which are: interaction, immersion, and imagination.

Interactive

The interactive feature enables a user to provide input and modify a virtual world instantaneously. In the DFSP tool, it enables a user to do a virtual site investigation and observation at any location in the virtually real construction project.

In order to execute the virtual site investigation and observation as effectively as the safety hazards identification task, VR functions are needed to be incorporated in the DFSP tool. There are four main VR functions developed in the DFSP tool: collision detection, terrain following, geometry picking, and VR tape measure. Hadikusumo and Rowlinson (2001) discussed further details of these VR functions, design, and development.

For the purpose of safety hazard identification, it is very important to understand the nature of the safety hazard. Most of the safety regulations note dimensions of an object as a safety requirement. For example, the CSSR of Hong Kong Schedule 3 notes that the minimum width of a working platform is 400 mm. In addition, if the working platform is used for material transportation, the minimum width is 650 mm. This indicates that a VR tape measure is needed to measure the dimension in the virtually real project for the purposes of safety assessment.

Immersive

The immersive feature facilitates a user to see a realistic looking world as well as to touch and feel it. This feature is used to represent and gather facts, which is representing virtually real construction components and processes (i.e., virtually real construction project), as defined in the functional requirements of the DFX shell of Huang.

The virtually real construction components represent construction products which are to be built on a construction project, e.g., walls, columns, and beams. The virtually real construction processes represent sequences of construction activities to install a construction component. The virtually real construction project is developed using VR software, World Up™. Details of the development of the virtually real project are discussed in Hadikusumo and Rowlinson (2001).

Imagination

The imagination feature enables a developer of VR to create an application that is able to solve a particular problem, such as representing the terrain of an area for flight simulation training to solve the problem of controlling a VR aircraft. In this study, this feature is used to solve the problem of safety hazards inherent within the virtually real construction project. Details of this feature are discussed in the next section.

Safety Hazard Identification and Accident Precaution

The DFSP tool is used for knowledge capture, safety planning, and a training tool. As a planning tool, the DFSP tool can assist a user in identifying safety hazards and determining accident precaution to avoid the occurrence of accidents in the hazards identified. For this purpose, the DFSP tool is equipped with a safety database. This database is designed based on ‘‘construction
components–possible safety hazards–accident precautions’’ relationships. One construction component can have many possible safety hazards, and one possible safety hazard can have many accident precautions. An advantage of using this relationship is that safety hazard information related to a construction component and its process of installation can be attributed to a construction component. In the construction process simulation, an installation process of an object can be identified from the component itself. If a user is seeing a precast facade being transported using a tower crane, it can be interpreted that he is seeing the installation process of a precast facade.

In the DFSP tool, the mechanism to retrieve the possible safety hazards from the DFSP tool safety database is based on keywords which are types of virtually real construction components, e.g., cast-in situ slab, and precast slab. For this, each virtually real construction component has a component type property. When a user selects a virtually real construction component, the DFSP tool retrieves and lists the possible safety hazards, which are related to the virtually real construction component, from the safety database. The user then can select, from the list, safety hazards occurring according to the conditions observed in the virtually real construction project. When the user selects a safety hazard, the DFSP tool retrieves and lists possible accident precautions. The user then can select, from the list, accident precautions to prevent accidents related to the safety hazard identified. Finally, this information—component name, component type, safety hazards identified, accident precaution, and time of installing the precaution—are documented in a safety plan.

For the purpose of a training tool, users can do a walk-through in a virtually real construction project and study possible safety hazards inherent within the project by using a DFSP tool safety database.

Capturing Construction Site Safety Knowledge from Engineers

The capturing of knowledge starts when safety engineers (i.e., users) observe the virtually real project and check possible safety hazards in conditions suggested by the DFSP tool safety database. The users can then recall their experience to check whether other possible safety hazards, which are not yet compiled in the database, exist. If other possible hazards may occur, the users can add new possible hazards by pressing the ‘‘New’’ button. Once safety hazards are identified, users can also consider safety accident precautions suitable to prevent accidents. For this, the DFSP tool lists accident precaution data related to the safety hazard identified and the user can choose accident precautions recommended by the database. Before deciding on an accident precaution, the users recall their experience to check whether other accident precautions, which are not yet compiled in the database, are also possible. If other accident precautions are also possible, users can create new accident precautions. These new safety hazards and new accident precautions will be printed in the safety plan discussed in ‘‘Safety Hazard Identification and Accident Precaution’’. In addition, if management consider that the new safety hazards and new precautions are effective for avoiding safety accidents, this new tacit knowledge can be stored by adding them permanently in the DFSP tool safety database [i.e., safety database: possible safety hazards–accident precautions. This illustrates that the DFSP tool provides a mechanism to capture the tacit contents of engineers’ safety knowledge.

Test Case Study

In order to test the capability of the DFSP tool to capture safety knowledge, test case studies were conducted. A typical floor of the Harmony Block of the HKHA public housing project is used as a virtually real construction project. The reason for using this project as a model is because this project type is the most commonly built HKHA public housing project; and therefore the tool and the knowledge captured can be reused in several projects.

Conclusion

Typically, safety engineers’ knowledge related to safety hazard identification and accident precaution is captured by discussions using 2D construction drawings and text data, such as method statements, and discussions on-site as case study tools. Both of the methods, however, have limitations. Therefore, in this research an innovative method is proposed to capture the knowledge by using the DFSP tool.

The DFSP tool is developed by using three major components: DFX, VR, and safety hazard identification and accident precaution database. One of its potential advantages is that it can be used to capture tacit knowledge (e.g., experience) residing in engineers’ minds, which is stored in an unstructured manner. The DFSP tool can be used to capture the tacit knowledge because: (1) VR can represent data in a WYSIWYG model which enables an engineer to understand a virtual object easier than if they are represented in 2D drawings; (2) VR can represent virtually real construction processes which also have safety hazards; and (3) the tool is equipped with a possible safety hazard database and accident precaution database which can stimulate the engineers to recall their experience.

This paper is part of the Journal of Construction Engineering and Management, Vol. 130, No. 2, April 1, 2004.

Abstract: An organization must strive to maintain its most valuable resource, knowledge, in order to be more productive and competitive. One of the steps to manage the knowledge is to capture contents of the knowledge. In construction site safety, success in capturing the tacit knowledge of safety officers is of paramount importance; however without a good mechanism, this process might be difficult due to time and hazard perception constraints. This paper discusses research in a design-for-safety-process tool, which aims at: (1) capturing safety knowledge from safety engineers about construction safety hazards and the safety measures required; (2) assisting a safety engineer to identify safety hazards in construction projects and determine the safety measures required; and (3) training students and inexperienced safety engineers in identifying safety hazards and the measures required. In this paper, the first objective is discussed.

DOI: 10.1061/(ASCE)0733-9364(2004)130:2(281)

CE Database subject headings: Accident prevention; Computer graphics; Computer aided simulation; Information management; Occupational safety; Safety factors.

1Assistant Professor, School of Civil Engineering, Asian Institute of
Technology, Pathumthani 12120, Thailand ^http://www.sce.ait.ac.th&.
E-mail: kusumo@ait.ac.th
2Professor, Dept. of Real Estate and Construction, The Univ. of HongKong, Hong Kong ^http://www.hku.hk&. E-mail: steverowlinson@hku.hk

Critical success factors influencing safety program performance in Thai construction projects

Thanet Aksorn *, B.H.W. Hadikusumo

Construction Engineering and Infrastructure Management, School of Civil Engineering,
Asian Institute of Technology, Pathumthani, Thailand

Introduction

In recent years, Thailand’s economy and infrastructure development have significantly and rapidly risen. The construction industry continues to play a major role in this development as many construction activities have been carried out to meet the high demands of the expansive market. However, the construction industry has faced a wide range of challenges, one of which is the frequent occurrences of accidents at the workplace. The risk of a fatal accident in the construction industry is five times more likely than in other industries (Sorock et al., 1993; Sawacha et al., 1999). Safety programs, a proactive approach, are one of best ways in improving site safety performance (Hislop, 1991; Tam et al., 2004). An effective safety program can substantially reduce accidents because it can help management to build up safer means of operations and create safe working environments for the workers (Anton, 1989; Abdelhamid and Everett, 2000; Rowlinson, 2003). Furthermore, by having an effective safety programs, good safety culture can be embedded in organization because it can encourage mutual cooperation between management and workers in the operations of the programs and decisions that affect their safety and health. The challenge of how to successfully put written safety programs into actual actions has gained considerable attention in the modern workplace. More than preventing injury to workers, successful safety programs can minimize damage to equipment and tools, loss of market competition, project delays, and damage to company image or reputation (Top, 1991; Michaud, 1995; Findley et al., 2004).

Although the linkage between safety programs and the actual state of safety has been studied extensively, minimal effort has been made to investigate factors contributing to successful implementation of such safety programs at construction sites (Meridian Research, 1994; Tam et al., 2001; Sawacha et al., 1999; Findley et al., 2004). In this regard, it is crucial to discover specific factors that are significantly important towards building successful safety programs leading to satisfactory outcomes. Some studies (e.g. Stranks, 2000; Rue and Byars, 2001; Rowlinson, 2003; Tam et al., 2004, Abudayyeh et al., 2006) have identified several factors contributing to successful safety programs such as worker involvement, management commitment, sufficient resource allocation and teamwork. However, most of them are descriptive reviews which focused on describing success stories of such factors on safety performance (Findley et al., 2004). These studies lacked detailed quantitative analysis and failed to prioritize the importance of those success factors. In addition, many factors needed to be grouped so that few and essential CSFs representing a wide variety of issues can be revealed. Therefore, this paper aims at identifying and quantitatively prioritizing the factors contributing to the successful implementation of construction safety programs based upon the respondents’ perceptions and grouping the factors into lesser dimensions by using factor analysis.

Construction site safety in Thailand

Following the financial crisis of 1997, Thailand has been making significant steps towards economic and infrastructure development and has thus become one of the newly industrialized countries. The vast domestic and foreign direct investments have been channeled towards construction works. Conversely, construction has been labeled by the general public as the most hazardous industry. International Labour Organization (2000) and Social Security Office (2005) pointed out that the expansion of Thailand’s construction activities has caused continuing increase in the reported number of accidents. In Thailand, the labour force is defined by the Labour Act B.E. 2541 as persons whose age lies between 15 and 59 years. Approximately, the total employed workforce is 34.5 million persons. The construction industry’s share of the total workforce is about 1.4 million workers or 8% of the total. According to the statistics of deaths and injuries in all industries recorded by Ministry of Labour (International Labour Organization, 2005), the rate of accidents and fatalities in Thai construction is reported as the highest. In 2003, the construction industry accounted for 14% of the total number of 787 deaths at work, and 24% of the total 17 cases of permanent disability. Additionally, Ministry of Labour revealed that construction workers are five times more likely to suffer permanent disability than workers in other industries.

Safety programs are now a key to eliminating work-related accidents and injuries. The Thai Government has taken significant steps in improving safety in the construction industry by promoting the establishment of safety programs at the enterprise level. Consequently, the Department of Labour Protection and Welfare launched the sustainable promotion plan through the facilitation of training and guidance for construction organizations, and enforcement of the basic elements of safety programs as stated by legislation. Yet, the accident occurrence rate in the construction industry still remains at unacceptable levels. Siriruttanapruk and Anuntakulnathi (2004) pointed out that the poor levels of safety in the Thai construction industry are primarily due to inadequate implementation of safety programs and weak enforcement of legislation. Therefore, it is worthwhile to conduct a research focused on investigating the key factors influencing the success of safety programs. The findings therefore can be used as a guideline by construction sites to achieve successful outcomes.

Construction safety programs

Several meanings of safety programs were defined by various researchers and most of them have similar inferences. Anton (1989) defined a safety program as ‘‘the control of the working environment, equipment, processes, and the workers for the purpose of reducing accidental injuries and losses in the workplace.’’ Similarly, Oregon Occupational Safety and Health Division (2002) described a ‘‘workplace safety and health program’’ as ‘‘a term that describes what people (business owners, managers, and employees) do to control injuries and illnesses at their workplace.’’ Rowlinson (2003) identified the objectives of creating a safety program at construction sites as a means to prevent improper behavior that may lead to accidents, to ensure that problems are detected and reported, and to ensure that accidents are reported and handled accordingly. Based on previous studies (Tam and Fung, 1998; Poon et al., 2000; Goldenhar et al., 2001; Hinze and Gambatese, 2003; Findley et al., 2004), some effective safety programs were identified as follows: comprehensive safety policies, safety committees, safety inductions, safety trainings, jobsite inspections, accident investigations, first aid programs, in-house safety rules, safety incentives schemes, control of subcontractors, selection of employees, personal protection programs, emergency preparedness planning, safety related promotions, safety auditing, safety record keeping, and job hazard analysis.

Factors affecting safety program implementation

Within the business context, the idea of identifying factors affecting the success of business- related activities and projects, often called critical success factors (CSFs), has existed for considerable time since initially popularized by Rockart (1979). The CSFs can be defined as ‘‘areas in which results, if they are satisfactory, will ensure success within and of the organization’’ (Rockart, 1979). According to Rungasamy et al. (2002), CSFs are essential to the success of any program, in the sense that, if objectives associated with the factors are not achieved, the program will perhaps fail catastrophically. In general, the success of safety programs arises from desired events or activities that are required to be happen. According to Top (1991) and Michaud (1995), a successful safety program can be measured in terms of no injury to people, no damage to equipment, machines and tools, no damage to environment, no loss of market competition, no damage to company image or brand-name, and increased productivities. Based on previous safety researches, 16 factors were commonly proposed as essential to favorable outcomes of safety program implementation. Table 1 summarizes and discusses the potential factors affecting the success of safety programs as sourced from safety literature.

Conclusions

This research identified and ranked 16 CSFs of safety program implementation based on their degree of influence. It revealed that ‘‘management support’’ was the most influential factor for safety program implementation in the Thai construction industry. The results of the 16 CSFs in the order of the degree of influence were: (1) management support, (2) appropriate safety education and training, (3) teamwork, (4) clear and realistic goals, (5) effective enforcement scheme, (6) personal attitude, (7) program evaluation,
(8) personal motivation, (9) delegation of authority and responsibility, (10) appropriate supervision, (11) safety equipment acquisition and maintenance, (12) positive group norms, (13) sufficient resource allocation, (14) continuing participation of employees, (15) good communication, and (16) personal competency. Additionally, there was a strong consensus on the rankings of these 16 factors between the two different groups of respondents. By using a Factor Analysis technique, the identified CSFs were grouped into four major dimensions namely, (1) worker involvement, (2) safety prevention and control system, (3) safety arrangement, and (4) management commitment. ‘‘Worker involvement’’ referred to creating favourable safety attitudes and motivation of workers which largely depended on constructive norms of the workgroup and their degree of their participation in safety activities. ‘‘Safety prevention and control system’’ required an effective enforcement scheme, appropriate supervision, equipment acquisition and maintenance, appropriate safety education and training, program evaluation and staffing qualified persons in order to successfully implement a safety program. ‘‘Safety arrangement’’ involved setting up proper mechanisms to disseminate information to all people concerned, assigning clear authorities and responsibilities to everyone at all levels as well as allocating adequate resources to safely carry out activities. ‘‘Management commitment’’ consolidated the safety program implementation through visible support of the top management which also included encouraging all employees to achieve success through team-spirit and setting realistic and achievable safety goals which could be accomplished. To ensure the contribution of the CSFs to the safety standards were realistic, three case studies were conducted. The results proved that the construction project, wherein all CSFs, and not just one or a few, are given proper attention, there is a higher standard of safety performance.

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The abstract is copied and posted.

Abstract

It is well known that construction projects have many work-related accidents and injuries. In recent year, to overcome such safety problems, safety program implementation has been given significant consideration as one of the effective methods. In order to effectively gain from safety programs, factors that affect its implementation need to be studied. This paper identified 16 critical success factors (CSFs) of safety programs from safety literature and previous research and these were thereafter validated by construction safety professionals. The study was conducted through questionnaire surveys with 80 respondents from medium and large-scale construction projects taking part. The survey intended to assess and prioritize the degree of influence of those success factors have on the safety programs as perceived by the respondents. The result showed that the most influential factor is management support. Furthermore, using factor analysis, the 16 CSFs could be grouped into four dimensions: worker involvement, safety prevention and control system, safety arrangement, and management commitment. In order to validate the findings, three case studies were further conducted to test the effect of those success factors on construction safety performance.

© 2007 Elsevier Ltd. All rights reserved.

Keywords: Critical success factor; Safety programs; Occupational safety and health; Construction; Employee involvement; Management commitment

* Corresponding author.E-mail address: st100549@ait.ac.th (T. Aksorn).