FACTORS AFFECTING IN THE PREPARATION OF CONSTRUCTION WORK SCHEDULE
FACTORS AFFECTING IN THE PREPARATION OF CONSTRUCTION WORK SCHEDULE JUSTIN BONG CHUNN TAT UNIVERSITI TEKNOLOGI MALAYSIA
DEC LA RA TIO N O F THESIS / PO STG RA DUA TE PRO JEC T PA PER A ND C O PYRIG HT
JUSTIN BO NG C HUNN TA T
Autho r’ s full na m e :
10 NO VEMBER 1985
Da te o f b irth
Title
FA C TO RS A FFEC TING IN THE PREPA RA TIO N O F
C O NSTRUC TIO N WO RK SC HEDULE
Ac a d e m ic Se ssio n :
I d e c la re tha t this the sis is c la ssifie d a s:
C O NFIDENTIA L
(C o nta ins c o nfid e ntia l info rm a tio n und e r the O ffic ia l Se c re t Ac t 1972)*
RESTRIC TED
(C o nta ins re stric te d info rm a tio n a s sp e c ifie d b y the o rg a nisa tio n w he re re se a rc h w a s d o ne )*
O PEN A C C ESS
I a g re e tha t m y the sis to b e p ub lishe d a s o nline o p e n a c c e ss (full te xt)
I a c kno w le d g e d tha t Unive rsiti Te kno lo g i Ma la ysia re se rve s the rig ht a s fo llo w s :
1. The the sis is the p ro p e rty o f Unive rsiti Te kno lo g i Ma la ysia . 2. The Lib ra ry o f Unive rsiti Te kno lo g i Ma la ysia ha s the rig ht to ma ke c o p ie s fo r the p urp o se o f re se a rc h o nly. 3. The Lib ra ry ha s the rig ht to m a ke c o p ie s o f the the sis fo r a c a d e m ic e xc ha ng e .
C e rtifie d b y:
SIG NA TURE SIG NA TURE O F SUPERVISO R
PRO F DR MUHD ZA IMI A BD MA JID
851110- 13- 6327
(NEW IC NO . / PA SSPO RT NO .) NA ME O F SUPERVISO R
Da te :
25 JUNE 2009 Da te :
25 JUNE 2009
NO TES : * If the the sis is C O NFIDENTIAL o r RESTRIC TED, p le a se a tta c h w ith the le tte r fro m the o rg a nisa tio n w ith p e rio d a nd re a so ns fo r c o nfid e ntia lity o r re stric tio n.
“I hereby declare that I have read this thesis and in my opinion this thesis is sufficient
in terms of scope and quality for the award of the degree of Master of Science (Construction Management)”
Signature
…………………………………… Name of Supervisor :
Prof. Dr. Muhd Zaimi Abdul Majid Date
30 JUNE 2009
FACTORS AFFECTING IN THE PREPARATION OF CONSTRUCTION WORK SCHEDULE JUSTIN BONG CHUNN TAT
A project report submitted in partial fulfillment of the requirements for the award of
the degree of Master of Science (Construction Management)
Faculty of Civil Engineering Universiti Teknologi Malaysia
30 JUNE 2009
“I declare that this project report entitled “Factors Affecting in the Preparation of Construction Work Schedule” is the result of my own research except as cited in the references. The report has not been accepted by any degree and is not concurrently
submitted by any candidature of any other degree.”
: JUSTIN BONG CHUNN TAT
Date
30 JUNE 2009
DEDICATION
Especially to my beloved father, mother, brother,
and all my friends.
ACKNOWLEDGEMENT
I wish to express my sincere appreciation to my supervisor Professor Dr. Muhd Zaimi Abdul Majid for his effort, encouragement and guidance.
In preparing this project, I was in contact with many industry practitioners. They have given me tips and useful information in order for me to complete the data sourcing. I am very thankful for them.
Last but not least, I am grateful to all my family members and friends for their support and understanding and providing me the fundamentals of character and work ethics to complete this task. Moreover, for their prayers, courage and understanding for me in my endurance to complete this mission.
ABSTRACT
Construction scheduling is widely used in many construction projects today but there still exists a large disparity in the proper use of this tool. Many projects schedule is created at the beginning of the project and never reviewed or revised until
a problem arises. Besides, contractors lack the skills necessary for preparing good construction schedule. Therefore, the objectives of this study are to investigate the factors affecting the preparation of better construction schedule; establish the severity of these factors; and the methods of improvements for preparing better construction schedule. Comprehensive literature review has been conducted to gather the information on the factors affecting the preparation of construction work schedule followed by structured questionnaire distribution as a main tool to gain data to establish the severity of these factors. The data attained were analyzed using average index and frequency analysis. From the analysis highlighted, there were thirty-five (35) factors where these factors were divided into four (4) main categories which were project specific factors, project management, working condition and external environment related factors. Hence, the results showed the top three factors that have the highest rank were complexity of project, identification of critical activities and type of project involved. In conclusion, the study also identified recommendations that can be used by the project participants in order to prepare effective and good construction work schedule in the local construction industry.
ABSTRAK
Penjadualan kerja pembinaan digunakan secara meluas dalam banyak projek- projek pembinaan hari ini tetapi cara penggunaannya masih tidak betul dan tepat. Kebanyakan penjadualan projek dihasilkan pada permulaan projek tidak pernah dikaji atau disemak semula sehingga sesuatu masalah muncul. Selain itu, ramai kontraktor tidak mempunyai kemahiran yang mencukupi dalam penjadualan kerja pembinaan. Oleh demikian, objektif kajian merangkumi penyiasatan factor-faktor dalam mempengaruhi persediaan penjadualan kerja pembinaan yang lebih baik, mengenalpasti tahap kritikal setiap faktor dan pengenalpastian kaedah peningkatan penyediaan jadual kerja pembinaan yang lebih berkesan. Kajian literatur secara komprehensif telah dilakukan untuk mengumpul maklumat mengenai faktor-faktor yang menyebabkan kelemahan prestasi projek prmbinaan melalui kajian sebelum ini. Seterusnya, kajian soal selidik telah dilakukan untuk mengumpul data bagi mengenalpasti tahap kritikal setiap faktor. Data-data yang diperolehi dianalisis menggunakan index purata dan analisis frequensi. Keputusan kajian menunjukkan terdapt 35 faktor penyebab dikenalpasti dimana faktor-faktor itu dibahagikan kepada
4 kategori utama iaitu faktor khusus projek; pengurusan projek; keadaan kerja dan faktor luaran. Dari analisis, 3 faktor utama yang mempunyai tahap kritikal tertinggi adalah kerumitan projek, pengenalpastian aktiviti-aktiviti genting dan jenis projek yang terlibat. Kajian ini juga memberi cadangan-cadangan yang boleh digunakan oleh pihak-pihak yang terlibat dalam projek untuk menyediakan jadual kerja pembinaan yang lebih efektif dan berkesan dalam ndustri pembinan tempatan.
TABLE OF CONTENTS
CHAPTER
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v ABSTRAK vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF APPENDIXES
xiv
1 INTRODUCTION
1.1 Introduction
1.2 Background of Study
1.3 Problem Statement
1.4 Aim and Objectives of the Study
1.5 Scope of the Study
1.6 Significance of the Study
1.7 Research Methodology
1.8 Summary
CHAPTER
TITLE
PAGE
2 LITERATURE REVIEW
2.1 Introduction
2.2 Importance of Construction Work Scheduling
2.2.1 Benefits of Construction Work Schedule
2.2.2 Developing a Construction Work Schedule
2.3 Construction Work Scheduling Techniques
2.3.1 Bar Charts
2.3.2 Critical Path Method
2.3.3 Choosing the Right Scheduling
Method
2.4 Developing Scheduling Specifications
2.5 Responsibility of Schedule Preparation
2.5.1 The Clients / Owners
2.5.2 The Construction Manager
2.5.3 The Designers
2.5.4 The Contractor and Subcontractors
2.5.5 The Design-Build Firm
2.5.6 Fabricators and Vendors
2.6 Sources of Planning Work Schedule
2.6.1 Construction Materials
2.6.2 Machineries and Equipments
2.6.3 Labours and Manpower
2.6.4 Finance
2.6.5 Time
2.7 Control and Monitor Construction Work Schedule
2.8 Characteristics of Good Construction Work Schedule
2.8.1 The Plan
2.8.2 Subcontractor Input
2.8.3 Schedule Card Trick
CHAPTER
TITLE
PAGE
2.8.4 Explicit Activities Name
2.8.5 The Right Level of Detail
2.8.6 Well Organized Activities
Groupings
2.8.7 Proper Consideration of Weather
2.9 Requirements of Successful Construction Work Schedule
2.10 Factors Affecting Preparation of Better Construction Work Schedule
2.10.1 Project Specific Factors
2.10.2 Project Management
2.10.3 Working Condition 41
2.10.4 External Environment
2.11 Summary
3 RESEARCH METHODOLOGY
3.1 Introduction
3.2 Literature Review
3.3 Methods of Data Collection
3.3.1 Primary Data Collection
3.3.2 Secondary Data Collection
3.4 Analysis Method
3.5 Reporting Results
3.6 Summary
4 DATA ANALYSIS AND FINDINGS
4.1 Introduction
4.2 Data Collection
4.3 Demographic Profile of Respondents
4.3.1 Respondent’s Highest Qualification
CHAPTER
TITLE
PAGE
4.3.2 Respondent’s Experience
4.3.3 Current Working Position
4.4 The Analysis of the Factors
4.4.1 Analysis of Projects Specific Factors
Considered
4.4.1.1 Average Index Analysis
4.4.1.2 Frequency Analysis
4.4.2 Analysis for Project Management Factors
Considered
4.4.2.1 Average Index Analysis
4.4.2.2 Frequency Analysis
4.4.3 Analysis for Working Condition Factors
4.4.3.1 Average Index Analysis
4.4.3.2 Frequency Analysis
4.4.4 Analysis for External Environment Factors 66
4.4.4.1 Average Index Analysis
4.4.4.2 Frequency Analysis
4.5 Analysis on Improvement Methods in Preparing Better Construction Work Schedule
4.6 Additional Suggested Factors Affecting In the Preparation of Construction Work Schedule
4.7 Discussion of Findings
4.8 Summary
5 CONCLUSION AND RECOMMENDATION
5.1 Introduction
5.2 Conclusion
5.3 Recommendations for future Study
5.4 Summary
CHAPTER
TITLE
PAGE
REFERENCES AND BIBLIOGRAPHY
APPENDIXES
LIST OF TABLES
CHAPTER
TITLE
PAGE
4.1 Project Specific Factors Considered in Preparing Better Construction Work Schedule
4.2 Project Management Factors Considered in Preparing Better Consruction Schedule
4.3 Working Condition Factors Considered in Preparing Better Construction Work Schedule
4.4 External Environment Factors Considered in Preparing Better Construction Work Schedule
4.5 Improement Methods in Preparing Better Construction Schedule
5.1 Factors Affecting the Preparation of Better Construction Work Schedule
5.2 Severity of Factors Affecting Preparation of Better Construction Work Schedule
LIST OF FIGURES
CHAPTER
TITLE
PAGE
1.1 Research Framwork Flow Chart
4.1 Highest Qualification of Respondents
4.2 Working Experience of Respondents
4.3 Working Position of Respondents
4.4 Project Specific Factors
4.5 Tabulatin of Project Specific Factors
4.6 Project Management Factors
4.7 Tabulation of Project Management Factors
4.8 Working Condition Factors
4.9 Tabulation of Working Condition Factors
4.10 External Environment Factors
4.11 Tabulation of External Environment Factors
4.12 Tabulation of Improvement Methods
LIST OF APENDIXES
CHAPTER
TITLE
PAGE
84
APPENDIX A
QUESTIONNAIRE FORM
CHAPTER 1 INTRODUCTION
The construction development projects are vastly increasing in Malaysia as the Government is taking the initiative towards making Malaysia a developed country by 2020. In association to that, the construction arena became the catalyst for this development purpose. Malaysian today is mesmerized by the unique development today namely the Kuala Lumpur Tower, The Petronas Twin Tower, Kuala Lumpur International Airport in Sepang and The North-South Light-Way- Transit. These have become the Malaysian’s pride.
Nevertheless, in ensuring these massive projects to be completed and utilized, some important elements must be considered, such as cost, time period and design quality. Thus, in this research, time factor for the completion of a project is crucial.
The construction development projects in Malaysia have adopted several scheduling and monitoring techniques to handle similar projects using manual or computer software operations. The clients monitor and check progress evaluations of work at site through his representative, the Superintending Officer or nominate other consultants.
Generally, the site supervisor will prepare scheduling reports to be evaluated and recommended by the client. The scheduling technique used will be the Precedence Diagram presented in the form of Microsoft Project or Primavera computer software.
This methods of scheduling is becoming more widely used in most of the construction projects especially Government projects. Thus, with this new technique, the process of construction in future can be identified and understood.
Therefore, research is done to identify factors affecting the preparation of a workable schedule of using Gantt chart, critical path method and other elements in the development projects in Malaysia. The usage of this method is predicted to reduce the problem of late possession of site and ensure that optimum cost, completion time and highest quality throughout the project.
1.2 Background of Study
Construction scheduling has come a long way in the last 25 years. Unfortunately, despite the widespread use of computerized scheduling on construction projects today, there still exists a large disparity in the level of understanding in the proper use of this powerful tool. According to Frank (2004), some even say there is a crisis in the construction industry because they believe scheduling software is being misused to assert delay claims and there is, in their view, a predominance of poor quality schedules.
The monitoring and control for construction projects sometimes cannot be seen on the whole and it takes a long time to reach a solution for any problem. The planning which is drafted together with current needs at that time will also give rise to late possession of sites and other problems regarding to site possession.
In association to that, the clients and contractors should be exposed to the importance and benefits of using work scheduling as an effective way to plan future work. The concept of work scheduling technique using critical path and Gantt chart gives a great impact on a project by assimilating every party involved in the construction project in reducing cost, shorten the time period and increase the quality of construction productivity.
Glenwright (2008) also stated that a characteristic of contemporary project scheduling is the over-simplification which stems from the inability of unaided human beings to cope with sheer complexity. Even though a detailed plan is necessary, the management also need only act when deviations from the plan occur.
A technique can be developed to resolve this situation that would be very simple but yet rigorous in application. One of the difficulties in the traditional approach is that planning and scheduling are carried on simultaneously.
Besides that, according to Twomey (2006), delivering a project on time relies on managing the development process, choosing experienced professionals, assessing timeframes realistically, and anticipating that some unforeseen problems are likely to come up. Aggressive management of typical scheduling issues that occur throughout construction can help ensure that projects are completed within the intended timeframe.
Hendrikson (2008) mentioned that in developing a construction plan, it is common to adopt a primary emphasis on either cost control or on schedule control. Some projects are primarily divided into expense categories with associated costs. In these cases, construction planning is cost or expense oriented. Within the categories of expenditure, a distinction is made between costs incurred directly in the performance of an activity and indirectly for the accomplishment of the project. For other projects, scheduling of work activities over time is critical and is emphasized in the planning process.
Traditional scheduling procedures emphasize the maintenance of task precedences (resulting in critical path scheduling procedures) or efficient use of Traditional scheduling procedures emphasize the maintenance of task precedences (resulting in critical path scheduling procedures) or efficient use of
According to Glenwright (2008), the first step was to separate the functions of planning from scheduling. The basic elements of a project are activities and resource expenditures and execution times are associated with each activity in the project. These factors, combined with technological relations, produce schedules proposing varying completion dates. Management comes into possession of a spectrum of possible schedules, each having an engineered sequence, a known elapsed time span, a known expenditure function, and a calendar fit.
In fact, Twomey (2006) stated that the key factors in keeping a project on track are to understand what causes delays and then to properly plan and manage schedule issues before they become problems. Delays of individual construction tasks may not be preventable. However, those that can’t be avoided do not necessarily have to hold up the entire project. The success of any construction project is based on balancing the resources of cost, quality, and schedule. All three of these issues are important. On many projects, however, time is the most critical issue for the overall success of the plan.
1.3 Problem Statement
Some project participants care more about their schedules than others. Some contractors prepare schedules only because it is a contract requirement. On far too many projects schedule is created at the beginning of the project and never reviewed or revised until a problem develops. The best approach is for all project participants to join in the scheduling process and develop a meaningful schedule, and then use it Some project participants care more about their schedules than others. Some contractors prepare schedules only because it is a contract requirement. On far too many projects schedule is created at the beginning of the project and never reviewed or revised until a problem develops. The best approach is for all project participants to join in the scheduling process and develop a meaningful schedule, and then use it
Besides, Harban Singh (2004) mentioned that work schedule submitted by the contractor should contain the main activities, sequence of activities, timing of activities, critical activities and critical path, and important milestones. Since there are no clear guidelines for the application of project scheduling in project management the current practice is entirely depending on the experience of the project manager. This has resulted in a lot of time wasting effort before parties involved in the project accept any work schedule.
Nevertheless, there are still weaknesses in term of formal guidelines for the preparation and submission of work schedule. Several problems associated with project scheduling are the inability to fully utilize the schedule, lack of understanding of scheduling techniques, and unable to see the importance of work schedule as stated by Mohamad Ibrahim et al (2006).
Furthermore, Jon et. al.(2002) said that as many contractors lack the skills necessary for successful scheduling, an owner may choose instead to provide to the contractor for successful scheduling consultant and may even pay for this service.
The participation of key subcontractors and suppliers to the development of a workable plan (detailed activity plans) is emphasized by Claugh and Sears (2000) and Walker (1996) who argues that construction planning and scheduling must be done by participation of people who are experienced in and familiar with the type of field work involved.
A similar idea is advocated by Ballard (1997) who emphasizes the idea of enabling what he calls the ‘‘Last Planner’’ participation in producing directives to drive direct work processes ‘‘assignments’’. He thinks that failing to prepare good assignments by planning at crew level, will prevent plans from being realized even if the upstream planning was good. The ‘‘last planner’’ principle requires selecting assignments from activities that are known to can be done. Without this has caused the uncertainty and variation of work flow, which results in less percentage of non- A similar idea is advocated by Ballard (1997) who emphasizes the idea of enabling what he calls the ‘‘Last Planner’’ participation in producing directives to drive direct work processes ‘‘assignments’’. He thinks that failing to prepare good assignments by planning at crew level, will prevent plans from being realized even if the upstream planning was good. The ‘‘last planner’’ principle requires selecting assignments from activities that are known to can be done. Without this has caused the uncertainty and variation of work flow, which results in less percentage of non-
However, it appears that it is not how often the network is recalculated or updated but instead it is how well the plan and schedule continue to fit the actual conduct of the work. As many of the key problems of implementation lie in the general environment of the project and not under the direct control of the project, project managers must look outside the project and ahead to anticipate problems and develop contingency plans. Kiiras (2001) stated that this can only be achieved by means of continuous planning and steering during project life instead of the traditional detailed project planning before the start and reporting during execution.
1.4 Aim and Objectives of the Study
The aim of this study is to identify the factors affecting in the preparation of construction work schedule.
To achieve the aim, the main objectives of this study are outlined as follows:
(1) To investigate the factors affecting in the preparation of better construction work schedule; (2) To establish the severity of these factors; and (3) To identify improvement methods in preparing better construction work
schedule.
1.5 Scope of the Study
The scope of study is confined to building projects undertaken by contractors registered with class G5 to G7 under Construction Industry Development Board (CIDB) in the locality of Johor.
1.6 Significance of the Study
The study intends to analyze and promote a better understanding and recognition of the complexities of the performance of contractors in completing projects. This study will offer some practical ideas, based on actual construction experience, to assist contractors in developing realistic construction schedules. It is intended to make the reader aware of certain aspects that frequently seem to be ignored and to alert owners to potential problems as well as possible courses of action to avert problems. The points outlined in the paper will also assist owners in evaluating the qualifications of potential contractors who may propose on building development projects.
1.7 Research Methodology
In achieving the results of this study, a pilot study is done to obtain opinion from various parties involved in the construction projects. From this study, a hypothesis shows that the schedules normally given to clients from the contractors are done using the critical path method or precedence diagram method rather than bar charts.
The approach for implementing this research is divided into a few categories. The purpose of this methodology is to simplify the process of data collection and other relevant information which is obtained throughout this research. The research framework flow chart is illustrated as show in Figure 1.1.
1.8 Summary
This research is a descriptive research and the type of research method used is questionnaire survey. The method of data collection is through questionnaire forms. The respondents are randomly selected from Classes G5 to G7 registered under the CIDB. After the primary data are sufficiently obtained, the data will then
be collected to achieve the objective of this study.
Initial Study
Identify Problem
Research of Statement
Importance
Objectives
of Study
Scope
Literature Review
Factors Affecting in the preparation of
Construction Work Schedule
Research Methodology
Data Collection:
Data Analysis:
1. Average Index
Discussion
2. Frequency Analysis
Conclusions and Recommendations
Figure 1.1: Research Framework Flow Chart
CHAPTER 2 LITERATURE REVIEW
CHAPTER 2 LITERATURE REVIEW
2.1 Introduction
This chapter covers the introductory of construction work schedule. The last part of this chapter will focus on the factors affecting in the preparation of construction work schedule with listing of all the possible factors adopted according to the suitability of the local construction industry.
2.2 Importance of Construction Work Scheduling
The importance of planning and scheduling in construction cannot be overestimated. The US Department of Labor, Bureau of Statistics, includes an industry definition of a Construction Manager (CM) that states they will typically schedule and coordinate all design and construction processes (USDL, 2005). In a study entitled “What does a Construction Manager really do?” performed by the Construction Management Association of America, it was found that one of the The importance of planning and scheduling in construction cannot be overestimated. The US Department of Labor, Bureau of Statistics, includes an industry definition of a Construction Manager (CM) that states they will typically schedule and coordinate all design and construction processes (USDL, 2005). In a study entitled “What does a Construction Manager really do?” performed by the Construction Management Association of America, it was found that one of the
The construction schedule is one of the most powerful management tools at the service of the construction manager. A well-planned and realistic schedule that takes into account as many variables as possible will help keep a construction project moving along smoothly, alert the construction manager when the project is about to run into snags, and help make needed adjustments when unforeseen circumstances arise. In order to do all that, though, the plan must have the input and some degree of ownership from everyone who will have to live by it. Otherwise, there is risk of having workers and subcontractors who are working against the construction schedule rather than with it.
The schedule is prepared by the scheduler and/or planner. In preparing a schedule, the scheduler or planner may meet or discuss with some people for crucial information, e.g. estimator, manager, superintendent, sub-contractor, architect, engineer, owner, and materials' suppliers. They may need to study the contract, drawings, specification, and perhaps, conduct site reconnaissance. Further, they need to know about manpower and productivity. Apart from the schedule, it is also necessary to prepare systematic monitoring to provide early warning of restraints as well as imaginative action to overcome them.
According to Jon et. al. (2002), the scheduling consultant should strive to develop a trusting relationship with the different participants to develop a workable plan and project schedule. Proper scheduling provides the best opportunity for a well- coordinated and well-sequenced project that is delivered on time and within all participants’ budget. This is because a well-coordinated and well-sequenced project is often difficult to achieve. He must work diligently with the project stakeholders who are the general contractor, the subcontractors, the construction manager, and the owner, to ensure the construction process participants are working collectively toward agreed- According to Jon et. al. (2002), the scheduling consultant should strive to develop a trusting relationship with the different participants to develop a workable plan and project schedule. Proper scheduling provides the best opportunity for a well- coordinated and well-sequenced project that is delivered on time and within all participants’ budget. This is because a well-coordinated and well-sequenced project is often difficult to achieve. He must work diligently with the project stakeholders who are the general contractor, the subcontractors, the construction manager, and the owner, to ensure the construction process participants are working collectively toward agreed-
2.2.1 Benefits of Construction Work Schedule
The Construction schedule major purpose is to map out the progress expected on a construction project in a timeline that is the most efficient and cost effective possible. It does this through various means, and serves a number of subsidiary purposes as well. These include:
(1) The original conceptual plan can help determine the feasibility of the project and give an idea of the estimated cost of the project; (2) It serves as a reasonable, understandable document upon which contractors and subcontractors can make realistic bids on the project; (3) It makes binding agreements with subcontractors. When a subcontractor signs the agreed-upon construction schedule, they are committing to meeting its terms;
(4) It gives the owner of the project a realistic timeline by which he can expect
his project to be completed. It lays out the sequence of events and the process that will be followed by the construction company and subcontractors, making it easier for him to monitor;
(5) It serves as a map and scheduling tool for the project manager, who can use it to schedule work crews, time deliveries and equipment rentals and monitor the progress in case of needed changes;
(6) It becomes a daily, weekly and monthly benchmark of the actual progress on
the project as the construction subcontractors and crew leaders enter finished jobs and concerns;
(7) It serves as a base plan for any changes that might have to be made due to unforeseen circumstances, unexpected delays (or completion ahead of schedule – it can happen!), or owner changes and additions;
(8) When coupled with communication and project management software, it is an effective, efficient way to track progress, and flag trouble spots before they become critical.;
(9) It serves as documentation of work completed as the concerned parties sign off on agreed upon completion; (10) In the event of dispute or questions, it can serve as legal documentation of the actual history and events of the construction; and (11) After project completion, it can serve as a guide in future projects through post-completion analysis.
2.2.2 Developing a Construction Work Schedule
Construction schedule specifications are all over the map. According to the committees of the Association for the Advancement of Cost Engineering (AACEI) and the Project Management Institute College of Scheduling (PMICoS) (2005), there is no consistency in arrangement, focus or language. Some specifications start right off with the software to be used along with the requirements for reports and updates. Others start with scheduler qualifications while still others introduce the purpose of the schedule and the schedule scope of work. Frequently, however, these procedures, processes and technical details are completely intermingled. At the same time, there are variances in common details, such as determination of lost weather days and the maximum duration of an activity. Some specs specifically require the qualification of the scheduler, while one owner offers to fund the scheduling services for the contractor.
The idea is that processes and procedures that are common to many specifications will be independent of the technical portions of the specifications. The mechanical details of the schedule and specific software requirements can reside in a technical section of the specification. Time extension requirements should be separate as well. Having a common framework of schedule specifications will lead to more consistency across contracts and will reduce confusion among the contractor community. Accomplishing general industry agreement on the procedures and process should be more achievable. Having a separate technical section may not necessarily lead to agreement on many details, but will at least lead to development of a checklist for owners to consider in their schedule specifications.
If today’s construction schedules are properly prepared, construction managers, owners, suppliers, and sub-contractors have an efficient and effective management tool to control complex construction projects accomplished by a diverse array of designers, engineers, suppliers, and specialty subcontractors. Planning, coordination, and communication of the work plan, schedule, performance, and control are then greatly facilitated in the efforts to achieve projects successfully and profitably. However, the ‘if’ needs to become ‘when’. And this means all of the underlying aspects need to be checked by an independent, qualified and experienced master construction scheduler and the validation-auditing team as stated by Glenwright (2008).
2.3 Construction Work Scheduling Techniques
The advantages to using a complete construction scheduling package include: immediate field updates; realistic revisions; input from those actually completing the work; and a stronger investment in completing the work according to schedule and on time. Onsite internet access to the construction schedule and communication capabilities give the project leadership the tools they need to provide onsite supervision that is responsive and decisive.
The nature of the project schedule will normally depend on the cost of the project. A bar chart is usually used on smaller projects. As the cost of the project increases owner’s start to demand a schedule that is based on a critical path method network.
2.3.1 Bar Charts
A bar chart simply indicates when specific activities will start date, their duration and finish date. The activities are plotted on a time scale. Since each specific activity on a bar chart is depicted as a straight line on the schedule, a bar chart is easy to understand. A bar chart does not indicate the interrelationship between different activities nor does indicate that the commencement of one activity is dependent on the completion of a predecessor activity.
2.3.2 Critical Path Method
It is important to understand the relationship between the commencement and completion of the various activities which comprise a construction project. Critical path method (CPM) network and Program Evaluation Review Technique (PERT) are the two scheduling devices which indicate the dependencies and interrelationships between different activities. Those interrelationships between activities are indicated as a network.
Over the years, the CPM has become the common construction network schedule. A CPM shows the sequence of each activity, the start of each activity, the Over the years, the CPM has become the common construction network schedule. A CPM shows the sequence of each activity, the start of each activity, the
The CPM is graphical model of a project. The basic components of the network are individual arrows which represent specific activities. The activity can
be any aspect of the project that requires either time or resources. The project activities are indicated by a logical flow of the work from the left hand side of the schedule to the right hand side. At each end of the arrow are activity numbers. The numbers are referred to as “i-j” designations. The letter “i” represents the start of the activity and the letter “j” represents the finish of the activity. At some place along the arrow and between the “i-j” designations is a number which represents the number of days that activity will require. The schedule also has a time scale. Finally, the critical path is shown as darker or different colored line that runs through the critical activities.
According to William (2009), the basic steps in creating a CPM schedule include: (1) identification of the basic tasks or activities that must be performed to complete the project; (2) estimation of the duration of the specific activities; (3) making a determination of the logical flow of the work, which includes a determination of which activities must be completed before the subsequent ones can commence; and (4) inputting the information into the computer so that it can make the numeric calculations that lead to the formulation of the schedule.
Terms that are used in context of a CPM network include:
(1) An Arrow or line is used to represent one activity; (2) A Node or Event which represents the beginning and ending point of an activity; (3) A Milestone is typically a significant event that the owner or contractor wants to track;
(4) A Link which represents the path between two Nodes; (5) A Dependency is the relationship between two different activities as
they related to the commencement and completion of those activities;
(6) A Predecessor activity is an activity that restrains ( refer to as a restrain ) a subsequent depend activity; (7) A the restrained activity that follows a Predecessor activity is a Successor activity; (8) Job logic refers to the necessary time and order of specific activities in relationship to the whole project; and (9) Float represents the number of days an activity can be delayed without delaying the project, with a critical activity having no float.
The critical path is computed in two steps. The first step involves a forward pass calculation of the activities; starting with the first activity on day one of the project. During the forward pass calculation the early start and early finish for that activity is calculated. The early start is the earliest time an activity can start and is based on the completion of predecessor activities. The early finish is the earliest time an activity can finish, assuming it starts on time and takes no longer than was planned. The second step is the backward pass calculation. It involves calculating the late start dates and late finish dates for each activity. While the late start date is the latest date an activity can start without delaying the project completion, the late finish date is the latest date an activity can finish without delaying the project. Scheduling software automatically completes these two calculation passes then prepares a report with the dates and a graphic network portrayal of the schedule.
The Critical Path is the longest continuous chain or series of activities through the CPM network. In essence, the critical path is the shortest period of time it will take to complete all the activities that comprise the project. The completion of project is delayed when one of the critical path activities is not started on time, not finished within the allotted time, or not finished on time. If a non-critical activity exceeds its float time, that activity will become critical.
2.3.3 Choosing the Right Scheduling Method
Jon et. al. (2002) mentioned that one of the key decisions to be made before
a project begins is which scheduling method is best suited to the project. Frequently, the owner and the designer decide on scheduling requirements as a part of the planning process for a project and the process of drafting specifications for bidding or negotiating. In making this decision, considerations were given to;
(1) The size, complexity, and location of the project; (2) Project phases and timing; (3) The number of parties that will act as prime contractors; (4) The need date for completion of certain milestones and of the project; (5) The experience of the owner, the architect/engineer, or the construction
manager in the use of specific scheduling techniques; (6) The capabilities and experience of the prime contractor(s) in preparing and implementing the project schedule required; (7) The type and quality of data desired by the owner, architect/engineer, construction manager, or contractor to effectively plan, schedule, coordinate, monitor, appraise, and document the progress of the project; and
(8) The amount of owner-furnished or third-party-furnished material and equipment involved.
Regardless of the scheduling system chosen, the owner or the owner’s agent responsible for managing the project should have experience with the scheduling method selected.
2.4 Developing Schedule Specifications
After an owner or agent has chosen the proper scheduling technique, either the critical path method (CPM) or the bar chart method, it is important to the success of the project that specifications outlining the scheduling requirements be carefully prepared and incorporated into the contract. Including such requirements enables an owner to more effectively control and enforce the scheduling obligations of the parties involved.
Schedule specifications should be clear and concise, avoiding ambiguities and potential misunderstanding. Unfortunately, this is not often the case. Frequently, specifiers have little knowledge of the scheduling technique being specified and the responsibilities and liabilities they can incur.
Experience has shown that it is very difficult to establish standard schedule specifications for use by the construction industry today. For example, specifications may range from one paragraph to five or ten pages. The short specifications are dangerous, and the long ones are expensive. However, experience has shown that the more detail included in the specifications, the better chance there is to eliminate misunderstandings.
Hence, Jon et. al. (2002) stated that good Construction work schedule specifications set forth the type of schedule that will be in effect for the project. Specifically, they address:
(1) The scheduling method and techniques to be used; (2) Which party has the responsibility for preparing the schedule; (3) Coordination of any multiple-contract situations that will exist on the
project; (4) The amount or level of schedule detail required by the specification; (5) The need to incorporate all contractually specified milestones. This may
include completion dates for critical components of work, deliveries of equipment, dates for promised information (such as owner-tenant include completion dates for critical components of work, deliveries of equipment, dates for promised information (such as owner-tenant
(6) The need for the contractor to identify dependencies that will restrain performance; (7) Processing procedures for shop drawings (preparation, submission, and approval); (8) Processing procedures for submittals (initial and updates, plus frequency); (9) Procedures for review and approval of the schedule;
(10) Remedies for noncompliance (for initial schedule as well as updates); (11) Updating procedures (specifying frequency, requirements for joint
updating meetings between parties, the keeping of meeting minutes, data requirements and methods for incorporating time-impact analyses and time extensions as part of the updating process);
(12) Progress reports; (13) Whether or not the schedule will be used for determining progress
payments; (14) Procedures for justification of time extensions (using time impact analysis); (15) Float utilization and availability to project and parties; and (16) Involvement of subcontractors in the scheduling process.
2.5 Responsibility for Schedule Preparation
In order for the construction plan to meet all these requirements, though, it must have the willing cooperation and buy-in of the owner, construction manager, sub-contractors and designers. In short, everyone needs to have some degree of ownership in the plan. For that reason, it’s important that the owner or construction manager to have the input of every major player in the project during the design stages of the construction schedule.
As early as the bidding stage, it pays to be open to suggestions and communication. Being open to input from bidding subcontractors allows the plan to
be refined based on the experience and capabilities of those who have tackled similar work in the past. If those lines of communication are open from the very start, every subcontractor who makes a successful bid has a realistic stake in the project because they feel they helped define the tasks and timetable. Without it, updating the schedule regularly becomes a time-wasting chore in their minds. When
a contractor and his crew have an investment in the plan, they feel they are helping to manage it rather than being a slave to it.
As quoted by Willis (1986), most of the following parties will be participants in a typical construction project. Women now play significant roles in all sectors of the construction industry, and it is expected that their participation in the industry will continue to increase.
Once the project delivery system and scheduling methods have been selected, the party responsible for preparing the project schedule must be designated. In the traditional approach, for example, an owner requires a general contractor to prepare the schedule. In addition, the owner has the option to require the general contractor to submit the schedule either for formal approval or for informational purposes only.
Under such circumstances, the general contractor also had options. For example, the general contractor may choose to prepare the schedule in-house or may contract the services of a scheduling consultant to provide technical assistance if the required skills and experience are not available in the general contractor’s organization. On occasion, an owner may specify that the general contractor hire a scheduling consultant and may even insist on approving the use of any consultant selected by the contractor.
As many contractors lack the skills necessary for successful scheduling, an owner may choose instead to provide to the contractor for successful scheduling consultant and may even pay for this service as referred by Jon et. al. (2002). This option also offers alternatives. For example, the scheduling consultant can work with the contracted party or parties and assist in developing a schedule for all work As many contractors lack the skills necessary for successful scheduling, an owner may choose instead to provide to the contractor for successful scheduling consultant and may even pay for this service as referred by Jon et. al. (2002). This option also offers alternatives. For example, the scheduling consultant can work with the contracted party or parties and assist in developing a schedule for all work
2.5.1 The Clients / Owners
This is the individual, the firm, or the organization that funds the construction project and will own the completed facilities. The owner, perhaps assisted by consultants, specifies the scope of the construction project.
In some instances, the owner may specify the detailed layout of the facility, the type of materials to be used, and so forth. The owner, perhaps assisted by some of the parties described below, and depending on the technical expertise of his or her own staff, may inspect the project work as it is being performed and on its completion. The golden rule in the construction process is: "He who has the gold makes the rules." Because the owner controls the purse strings, he or she dictates the kind of contract that will be used and selects the other parties to the project.
2.5.2 The Construction Manager
He or she is an employee of a professional construction management firm that may be retained by the owner to perform predesigned planning, to help select the designer, to help select contractors, and to perform post-contract award functions. The construction management firm may perform all or some of these functions in return for a fee. When capitalized, the term Construction Manager (CM) means an He or she is an employee of a professional construction management firm that may be retained by the owner to perform predesigned planning, to help select the designer, to help select contractors, and to perform post-contract award functions. The construction management firm may perform all or some of these functions in return for a fee. When capitalized, the term Construction Manager (CM) means an
When an owner contracts the services of a construction manager as his agent, the construction manager is frequently responsible for overall scheduling and coordination when multiple trade or multiple prime contracts are used. As a result, the construction manager has several options schedule development and implementation.
The construction manager may prepare an overall detailed master schedule for the project. This type of schedule usually be supported by milestone schedules and/or prebid integrated schedules for each of the key multiple prime or trade contracts that are anticipated to be let with this method of the project delivery.
As trade contractors are let, the construction manager has the option to require each trade contractor to participate jointly in the development of the trade contract schedule. The objective is to reflect the trade in the development of the trade contract schedule. The objective is to reflect the trade contractors’ plans and intentions to execute their work and to coordinate their dependencies with others.