Construction Delay Analysis under Multiple Baseline Updates By Wail Menesi A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Applied Science in Civil Engineering Waterloo, Ontario, Canada, 2007 © Wail Menesi 2007 I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. Wail Menesi ii ABSTRACT Due to the inherent risks and increasing complexity of modern construction projects, delays and cost overruns have become common facts in the industry. Researchers and practitioners have used many techniques to assess project delays and apportion delay responsibility among the parties involved. Windows delay analysis has been recognized as one of the most credible techniques for analyzing construction delays. Despite its benefits, windows analysis can produce different results depending on the window size, it does not consider owner and contractor acceleration, it does not systematically consider the impact of several baseline updates made due to changes in the duration and logical relationships of the activities, and it does not consider the impact of the progress events on resource over-allocation and its consequent delays. This study proposes a computerized schedule analysis model that considers multiple baseline updates and resource over-allocation. The model uses a daily window size in order to consider all fluctuations in the critical path(s) and uses a legible representation of progress information to accurately apportion delays and accelerations among project parties. To facilitate its use, the model has been incorporated into a computer tool, EasyPlan, which integrates estimating, scheduling, resource management, and project control. A simple case study has been implemented on the proposed delay analysis model in order to demonstrate its accuracy and usefulness. iii ACKNOWLEDGEMENT I would like to express my sincere appreciation and gratitude to my supervisor, Dr. Tarek Hegazy, for his invaluable guidance, patience, kindness, and respect. I am deeply impressed with his wealth of knowledge, excellence in teaching, and dedication to academic research. I would also like to express my sincerest gratitude to my parents, whose love and support made this work possible. Above all, praise is to God. iv To My Parents v TABLE OF CONTENTS Abstract iii Acknowledgements iv Dedication v Table of Contents vi List of Figures ix List of Tables xiii 1 Introduction 1 1.1 Construction Delays………………………………………………….. 1 1.2 Research Motivation ………………………………………………….. 2 1.2.1 Problem with Window Size ………………………………….. 3 1.2.2 Inadequate Consideration of Acceleration…………………. 3 1.2.3 Inadequate Consideration of Baseline Changes Along the Project……………………………………………………………. 4 1.2.4 Inadequate Consideration of Resource Over-Allocation in Delay Analysis……………………………………………………. 5 1.3 Research Objectives and Scope ……………………………………. 5 1.4 Research Methodology ………………………………………………. 6 1.5 Thesis Organization …………………………………………………... 6 2 Literature Review 8 2.1 Introduction …………………………………………………………... 8 vi 2.2 Causes of Delays …………………………………………………… 9 2.3 Types of Delays …………………………………………………….. 11 2.4 Types of Schedules Used in Delay Analysis …………………….. 13 2.5 Recording Site Events for Delay Analysis ………………………... 13 2.6 Delay Analysis Techniques ………………………………………… 18 2.6.1 The As-Planned Versus As-Built Comparison ……………. 18 2.6.2 The impacted as-planned method (What-If approach)…………………………………………… 18 2.6.3 The Collapsed As-Built Method (But-For Method) ……….. 19 2.6.4 The Contemporaneous Period Analysis Method (window analysis) …………………………………………… 20 2.7 New Developments …………………………………………………. 26 2.7.1 Improved But-for Analysis …………………………………… 27 2.7.2 Improved Windows Analysis ………………………………... 28 2.7.3 Other Approaches ………………………………………….. 29 2.8 Conclusion …………………………………………………………… 30 3 Daily Windows Analysis with Multiple Baseline Updates 31 3.1 Introduction …………………………………………………………... 31 3.2 Daily Windows Analysis ……………………………………………. 31 3.3 Baseline Updates …………………………………………………… 36 3.4 Case Study Involving Multiple Baseline Updates ……………….. 36 3.5 Detailed Procedure …………………………………………………. 44 3.6 Conclusion …………………………………………………………… 47 vii 4 Daily Windows Analysis with Resource Allocation 48 4.1 Introduction ………………………………………………………….. 48 4.2 Resolving Resource over-Allocation………………………………. 49 4.3 Delay Analysis with Resource Allocation …………………………. 51 3.3.1 Analysis Using Traditional Daily Windows Analysis ……… 53 3.3.2 Analysis Using Modified Daily Windows Analysis ………… 55 4.4 Detailed Procedure …………………………………………………. 58 4.5 Conclusion …………………………………………………………… 63 5 Integrated Model: Prototype and a Case Study 64 5.1 Introduction …………………………………………………………... 64 5.2 Case Study …………………………………………………………... 64 5.3 Modified Daily Windows Prototype ……………………................. 66 5.3.1 Activities and Schedule ……………………………………… 67 5.3.2 Actual Progress Events ……………………………………… 70 5.3.3 Multiple Baselines and Resource Challenge ……………… 73 5.3.4 Delay Analysis ………………………………………………... 79 5.3.5 Discussion of Results………………………………………… 80 5.4 Conclusion …………………………………………………………… 86 6 Conclusions 87 5.1 Conclusions ………………………………………………………….. 87 5.2 Future Research and Developments ……………………………… 89 References 91 viii LIST OF FIGURES Figure 2.1 Types of Delays …………………………………………………. 11 Figure 2.2 Recording Site Data in a Bar Chart (Based on Scott 1990) … 15 Figure 2.3 Representing Delays on Commercial Scheduling Software (Based on Stumpf 2000) ……………………………………….. 16 Figure 2.4 Recording Site Data Using Intelligent Bar Chart (Based on Hegazy et al., 2005) ………………………………... 17 Figure 2.5 Bar Charts for a small example of Windows Analysis ………. 22 (a) As-Planned Bar Chart ………………………………………. 22 (b) As-Built Bar Chart …………………………………………… 22 Figure 2.6 Windows Analysis Method with Two Windows, Ending at Days 3 and 9 ………………………………………………….. 24 (a) Window Ending at Day 3 …………………………………… 24 (b) Window Ending at Day 4 …………………………………… 24 Figure 2.7 Windows Analysis Method with Two Windows, Ending at Days 4 and 9 ………………………………………………….. 25 (a) Window Ending at Day 4 …………………………………… 25 (b) Window Ending at Day 9 …………………………………… 25 Figure 2.8 Concurrent Delay Representation Using A Venn Diagram …. 28 Figure 3.1 Entering the Daily Events ………………………………………. 32 Figure 3.2 Daily Windows Analysis Showing the window of day 3 ………34 Figure 3.3 Daily Windows Analysis Showing the window of day 4……… 34 Figure 3.4 Daily Windows Analysis Showing the window of day 5 ………35 Figure 3.5 Planned and Actual Progress of the Sample Case ………….. 37 (a) As-Planned Schedule……………………………………….. 37 (b) As-Built Schedule……………………………………………. 37 Figure 3.6 Representation of Project Timeline as A Film Strip………….. 38 Figure 3.7 Delay Analysis with Multiple Baseline Updates (window of day 1) …………………………………………………………….. 39 ix Figure 3.8 Delay Analysis with Multiple Baseline Updates Showing the Window of Day 2 before the Baseline Updated………………. 40 Figure 3.9 Delay Analysis with Multiple Baseline Updates (window of day 2) …………………………………………………………….. 40 Figure 3.10 Delay Analysis with Multiple Baseline Updates (window of day 3) …………………………………………………………….. 41 Figure 3.11 Delay Analysis with Multiple Baseline Updates (window of day 4) …………………………………………………………….. 42 Figure 3.12 Delay Analysis with Multiple Baseline Updates (window of day 5) …………………………………………………………….. 42 Figure 3.13 Delay Analysis with Multiple Baseline Updates (window of day 6) …………………………………………………………….. 43 Figure 3.14 Delay Analysis with Multiple Baseline Updates (window of day 10) …………………………………………………………… 43 Figure 3.15 Daily Windows Analysis with Multiple Baseline Updates Procedure ………………………………………………………... 46 Figure 4.1 As-Planned and As-Built Schedules of a Simple Case Study 52 (a) As-Planned Schedule ………………………………………. 52 (b) As-Built Bar Schedule……………………………………….. 52 Figure 4.2 Traditional Daily Windows Analysis (window of day 2) ……… 53 Figure 4.3 Traditional Daily Windows Analysis (window of day 3) ……… 54 Figure 4.4 Traditional Daily Windows Analysis (window of day 4) ……… 54 Figure 4.5 Modified Window of Day 2 ……………………………………… 56 (a) Before Resource Allocation…………………………………. 56 (b) After Resource Allocation…………………………………… 56 Figure 4.6 Modified Window of Day 3 ……………………………………… 56 Figure 4.7 Modified Window of Day 4 ……………………………………… 57 Figure 4.8 Daily Windows Procedure without Considering Resource Allocation …………………………………………………………. 61 Figure 4.9 Considering Resource Allocation in the Analysis ……………. 62 x