Pakistan with a population of over 180
million stands amongst the fastest urbanizing countries in the world. With an
urban growth rate of 3.5% annually, the urban population of Pakistan is above
36 percent which will become more than 50% up to 2050 (Zaidi, 2011). Given the situation
there is a need for long term planning for the development of adequate
infrastructure to cater for the growing residential and commercial needs of the
fast growing population of the urban centers of Pakistan. Hence, construction
of multi-storey buildings is a genuinely felt and pursued need in the urban
cities of Pakistan. Being a low income economy with only 2.3% of GDP (Economic
Survey of Pakistan) contributed by its construction sector, Pakistan needs to find
out ways which can help produce low cost and high quality multi-storey
buildings.
According to Mehmood et. al. (2012) construction sector of
Pakistan has tremendous potential to improve the quality of its construction
projects and make them more profitable and productive if it can effectively
control the wastages and costs of its construction processes effectively. This obviously
requires focusing on effective crew balancing, material management as well as equipment
and machinery handling besides improving sequencing of critical construction activities
in the construction of multi-storey buildings in Pakistan. Pakistani
constructors have been traditionally relying on methods such as CPM, Primavera
etc. It is, therefore, imperative to respond to the research questions such
as how the sequencing of construction activities controls cost and quality in
the construction of multi-storey buildings? And how the modern concepts of sequencing
of construction activities vis-à-vis resource utilization can help Pakistan
produce low cost and high quality multi-storey buildings? Ms. Sidra Maqsoom
made a case study aimed to:
(i) identify sequencing practices being
followed by Pakistani contractor firms for the
construction of multi-storey buildings
(ii) analyze how the critical activities
are sequenced for the construction of multi-storey
buildings of Pakistan and their impact on
cost and quality control.
(iii) understand relationship between
sequencing of critical activities and factors such as
crew balancing, material management and
equipment & machinery handling and their
influence on cost and quality control.
(iv) propose recommendations for
sequencing of critical activities and resource balancing
such that it reduces the cost and increases quality of
multi-storey buildings.
Conclusion
1. Sequencing
Practices of Pakistani Contractor Firms
In order to achieve this
objective, first an extensive literature review was done. CPM based sequencing practices
were identified and understood. These included approaches like Line of Balance (LOB),
Formalization, Simulation and Resource Activity Critical Path Method (CPM). A synthesis
of these concepts was drawn into a framework named Synthesis of Sequencing Framework (SSF) incorporating the
fundamental concepts underpinning each idea. This framework was then translated
into a survey questionnaire into various easy to understand questions to record
responses of Pakistani contractor firms on rating scales. These scales measured
their general awareness of these concepts, application to real time situation
and personal observations and experiences about the utility of these ideas
during project execution with special reference to cost and quality control.
The data was collected from 32 Pakistani contractor firms registered with
Pakistan Engineering Council (PEC). It was found that respondents were
generally aware and recognized various phases of construction and the critical activities
involved to be achieved in specified timelines. They understood that how much
the time factor is critical to control cost. Importance of resource management
such as men, material and machinery in cost management was also agreed by a
vast majority of respondents. They appreciated the idea that in case resources
are short, then measures such as flexibility in timelines or mobility of
resources between various activities are necessary. They believed that CPM is a
widely used technique of sequencing of critical activities used by Pakistan
contractor firms, however, there could be other methods and techniques which
can be used to control cost and quality such as doing various activities in
parallel rather than linear fashion to control cost. Reducing idleness of
labor, improved machinery and equipment management according to standardized
practices and material handling in a manner that improves efficiency and
reduces wastage are also significant during the construction process of
multi-storey buildings.
2. Sequencing and Resource Balancing and its
relationship with Cost and Quality
Control
Second and third objectives were
set to understand the relationship between sequencing and resource management
with cost and quality control during various phases of construction of multi-storey
buildings. Literature available on the issues such as critical activities,
sequencing practices, modern and standardized practices for effective and
efficient crew management, material handling and equipment and machinery
management was explored in detail. Based upon the literature reviewed, two
frameworks named Integrated Sequencing Framework (ISF) and Integrated Resource
Balancing Framework (IRBF) were developed. Two case studies were done for a
commercial cum residential and official multi-storey buildings were conducted
using these frameworks. It was found during the analysis that sequencing done
initially during the planning stages of projects are not always followed and
keep changing due to various factors. These
factors involve legal issues, procedural problems, design changes, withdrawal
or addition of works by the clients, environmental concerns etc. The delays in
sequencing cause cost increases. Similarly, defiance from standardized
practices of men, material and machinery management also results in coast
increases. As far as the quality controls are concerned they are to be
exercised both from internal as well as external means. Internal controls
involve having material testing labs, recruitment of quality control engineers
and developing linkages with public and private sector quality control
organizations. External controls are exercised by public sector organization’s
requirements to be complied with, clients satisfaction etc.
Recommendations
Objective four of the study was to
propose recommendations for sequencing of critical activities under each
construction phase, such that, it reduces the cost and increases quality of
multi-storey buildings. To achieve this objective, the following
recommendations have been proposed in light of the issues and problems noticed
during the analysis done both for quantitative and qualitative research
mentioned:
A) Related to
Sequencing
1. Planning Engineers should involve all
possible stakeholders during the making of initial schedule of work like design
engineers, client, consultants, site engineers and concerned government
agencies like development authorities, environment control organizations etc.
to minimize post execution changes.
2. To avoid post execution litigations,
the bye laws and buildings regulations should be strictly adhered to. In case
of any deviation special approvals should be obtained beforehand following the
requisite procedures.
3. To avoid delays in inspections by the
government led teams inspection schedules should be sent in advance by the
contractor well before the completion of the stage of construction to be
inspected.
4. Contractors should have guarantees
from the clients in advance that they have sufficient amount reserved in the
name of the project under execution to avoid delays in payments.
B) Related to Crew
Management
1. To avoid seasonal shortage of
unskilled workers contractors need to raise wages during sowing and harvesting
seasons.
2. To control work idleness, instead of
focusing on the working hours performance standards be set to be achieved on
daily, weekly and monthly basis.
3. Contract agreements between skilled
workers and contractors be signed to avoid their early drop outs and resultant suspension
of work.
4. To avoid idleness the labor force can
be engaged in other activities which can go in parallel to another activity.
C) Related to Material
Management
1. To overcome the problem of restricted
movements at main roads, the number of material laden trucks should be
increased at main roads rather than moving less truck in less time.
2. To avoid wastage of material due to
weather tarpaulin, material should be used during odd weather.
3. Procurement procedures should be
simplified by using IT based software to avoid delays and resultant increase in
price of material.
4. Soil testing labs should get their
samples tested from the soil testing and conservation departments as well
rather than relying on limited number of labs.
5. Standardized samples of material
required are kept available for comparison with the new purchase to achieve
uniformity in the quality of material
D) Related to Equipment
and Machinery Handling
1. Stock / inventory registers be updated
on regular intervals to know the condition of the machinery.
2. Use of a specific implement, equipment
be monitored in terms of its recommended frequency in a day or so to reduce
wear and tear.
3. Mutual exchange between projects
located in same area should be managed by a proper command and control system.
4. Only skilled and dedicated operators are
deputed with tasks of machinery handling rather than adhoc arrangements.
5. Placement of machinery at project site
should be in a manner that it does neither create any pollution nor is injurious
to environment.
Her thesis abstract is copied below.
Abstract
Pakistan with a population of
over 180 million is one of the fast urbanizing countries of the world. By 2050
the urban population of the country is estimated to be more than half of the total
population of the country. This requires to develop adequate infrastructure
such as multi-storey buildings to cater to the growing urban needs and
shrinking space in the urban centers of Pakistan. Being a low income economy
Pakistan needs to find out ways through which low cost and high quality
multi-storey projects could be produced. Previous researches have shown that Pakistan
can increase the quality and profitability of its construction projects by
improving the construction processes. These processes mean the construction
activities and the resources such as workforce, materials used and
the equipment and machinery handling. This research study has reviewed the literature available
on the sequencing practices being used in modern day construction industry as
well as the best practices recommended for adequate resource balancing to
achieve efficiency in construction projects. A generic model on sequencing
practices has been developed with the objective to understand what kind of
sequencing trends are followed by Pakistani construction firms. An integrated
framework on sequencing and an integrating resource balancing framework has
also been developed to achieve the objective of analyzing that how sequencing
and resource balancing practices of Pakistani construction firms within
conventional CPM schedules effect cost and quality control in different phases
of construction of multi-storey buildings of Pakistan such as foundation,
structure, architecture, electrical and mechanical installations and finishing.
A quantitative as well as
qualitative research has been undertaken to achieve the above mentioned
objectives. Quantitative research has been done through a questionnaire survey.
Whereas, the qualitative research has been carried out in a case study mode.
Based upon the findings of these two approaches some tenable recommendations
have been suggested for the Pakistani contractor firms to bring improvements in
sequencing and resource balancing practices to achieve efficiency in
construction projects characterized by reduced cost and enhanced quality.
Key Words: Multi-Storey Buildings,
Sequencing, Construction Activities, Resource
Utilization, Cost and Quality Control
No comments:
Post a Comment