the dynamics of float, logic, resource allocation, and delay timing in forensic schedule analysis and construction delay claims

The Dynamics of Float, Logic, Resource Allocation, and Delay Timing in
Forensic Schedule Analysis and Construction Delay Claims

By

Long Duy Nguyen



KY SU (Ho Chi Minh City University of Technology, Vietnam) 1999
M.ENG. (Asian Institute of Technology, Thailand) 2003
M.S. (University of California, Berkeley) 2005


A dissertation submitted in partial satisfaction of the

requirements for the degree of

Doctor of Philosophy

in

Engineering-Civil and Environmental Engineering

in the

Graduate Division

of the

University of California, Berkeley


Committee in charge:

Professor C. William Ibbs, Chair
Professor Glenn Ballard
Professor Frederick Collignon
Professor Arpad Horvath



Fall 2007





The dissertation of Long Duy Nguyen is approved:




Chair __________________________________________ Date _________________

__________________________________________ Date _________________

__________________________________________ Date _________________

__________________________________________ Date _________________





University of California, Berkeley
Fall 2007


The Dynamics of Float, Logic, Resource Allocation, and Delay Timing in
Forensic Schedule Analysis and Construction Delay Claims


Copyright 2007

by

Long Duy Nguyen
1

Abstract
The Dynamics of Float, Logic, Resource Allocation, and Delay Timing in
Forensic Schedule Analysis and Construction Delay Claims
By
Long Duy Nguyen
Doctor of Philosophy in Engineering-Civil and Environmental Engineering
University of California, Berkeley
Professor C. William Ibbs, Chair

Delay claims in construction projects present various tough and controversial issues.
How to prove the three elements, namely entitlement, causation, and quantum in the
“triad of proof” is an onerous task. The analyses of schedule delays and their associated
damages especially concern claims analysts, project parties, courts, Boards of Contract
Appeals, and so forth. On the one hand, the industry has employed various forensic
schedule analysis techniques to support delay claims. Paradoxically, schedule-related
factors such as float, logic, and resource allocation are frequently ignored even though
they can affect project completion time and delay responsibility, too. On the other hand,
the current “one-size-fits-all” methods for calculating financial consequences undermine
the relative importance of delayed activities and the fluctuating nature of overhead levels.
The effects of the context of a delay in terms of the timing of the delay and degree of
suspension should be therefore paid attention in quantifying delay damages.
Accordingly, this research develops novel techniques for analyzing causation and
calculating damages in construction delay claims. They address the dynamics of float,
2

logic, resource allocation and the delay context in forensic schedule analysis and delay
claims. Several published and hypothesized case studies are used to illustrate their
applications.
Among other things, this research proposes: (1) an enhanced window analysis
technique considering resource allocation; (2) an activity-specific overhead allocation
process (ASAP) for quantifying field-overhead damages; (3) FLORA as a novel forensic
schedule analysis technique that can capture the dynamics of float, logic, and resource
allocation; and (4) a framework which integrates FLORA and ASAP for analyzing
schedule delays and their field overhead damages in a real-time and interactive manner.
Through the applications, comparisons, and evaluations in case studies, these
developments really overcome various limitations of the available techniques and
practices currently used in forensic scheduling and delay claims.
This research recommends that the schedule-related factors should be captured in

forensic schedule analysis. In addition, the quantification of delay damages should
emphasize the context of a delay. This also enables equitable apportionments when
concurrent delays occur. ASAP and FLORA developed in this research are able to tackle
these issues.

__________________________________________
Professor C. William Ibbs
Dissertation Committee Chair
i






To my Mom and Dad
guyen Thi goc Lan and guyen Van Quy

Kính Tặng Ba Mẹ
guyễn Văn Quy và guyễn Thị gọc Lan
ii

Table of Content

Table of Content ii
List of Figures ix
List of Tables xi
Acknowledgements xii
Abbreviations xiv
Symbols xvi

Chapter 1 1
Introduction 1
1.1 Background 1
1.2 The Need for Research 2
1.3 Problem Statement 6
1.4 Research Objectives 7
1.5 Scope of Work 8
1.6 The Structure of the Dissertation 9
Chapter 2 11
Literature Review 11
2.1 Scheduling Practices in Delay Claims 11
2.1.1 Types of Schedules 12
2.1.2 The Use of the Critical Path Method 13
2.2. Roles of Project Change in Delays and Disruptions 14
2.2.1 The Concept of Project Change 14
iii

2.2.2 The Extent of Project Change 15
2.3 Delay, Disruption, Acceleration, and Delay Concurrency 16
2.3.1 Delay, Disruption, and Acceleration 16
2.3.1.1 Delays 16
2.3.1.2 Delay versus Disruption 17
2.3.1.3 Delay versus Acceleration 19
2.3.2 Causes and Costs of Delays 22
2.3.3 The Types of Delays 23
2.3.4 Concurrent Delays 25
2.3.4.1 The Concept of Concurrent Delays 26
2.3.4.2 Conditions for Occurrence of Concurrency 27
2.3.4.3 Apportionment of Concurrent Delays 28
2.4 Float and Criticality in Project Schedules 32

2.4.1 Float 32
2.4.2 Float versus Criticality 33
2.4.3 Float Ownership 34
2.4.4 Alternatives to Float Distribution and Management 35
2.5 Process of Forensic Schedule Analysis 37
2.6 Forensic Schedule Analysis Techniques 39
2.6.1 Global Impact Method 41
2.6.2 As-Planned vs. As-Built Method 41
2.6.3 Impacted As-Planned Method 42
2.6.4 Collapsed As-Built Method 43
iv

2.6.5 Schedule Window Analysis 44
2.6.6 Time Impact Analysis 45
2.6.7 Other Schedule Analysis Techniques 46
2.6.8 Criticism of Available Schedule Analysis Techniques 48
2.7 Delay Damages and Commonly Applied Methodologies 49
2.7.1 Overview of Delay Damages 49
2.7.2 Owner’s Delay Damages 50
2.7.3 Contractor’s Delay Damages 51
2.7.3.1 Types of Recoverable Damages 51
2.7.3.2 Equitable Adjustments 52
2.7.3.3 Field Overhead Damages 52
2.7.3.4 Extended HOOH versus Unabsorbed HOOH 54
2.7.3.5 Methodologies for Calculating HOOH Damages 55
2.8 Summary of the Literature Review 62
Chapter 3 63
Research Methodology 63
3.1 Research Framework 63
3.2 Bases, Tools, and Techniques 66

3.2.1 Current Forensic Schedule Analysis Techniques 66
3.2.2 CPM, Linked Bar Charts, and Resource-Constrained Scheduling 67
3.2.3 Scheduling Software Packages 67
3.2.4 Project Overhead Allocation 67
3.2.5 Research Evaluation 70
v

3.3 Data Sources 71
Chapter 4 72
Impacts of Resource Allocation on Forensic Schedule Analysis 72
4.1 Introduction 72
4.2 Motivating Case 73
4.3 Window Analysis under the Effect of Resource Allocation 75
4.4 Case Study 78
4.4.1 Case Overview 78
4.4.2 Analysis of Delays 79
4.5 Discussion 84
4.5.1 Possible Extended Effect of Delays 84
4.5.2 Positive/Negative Effect of Resource Allocation on Delay Responsibility 85
4.5.3 Legal Acceptability 85
4.5.4 Implications of Applying the Enhanced Window Analysis 86
Chapter 5 89
Delay Damages and Schedule Window Analysis 89
5.1 Introduction 89
5.1.1 Delay Context versus Delay Responsibility 90
5.1.2 Field Overhead Damages 94
5.2 An Integrated Approach 95
5.3 Hypothetical Case Study 98
5.4 Discussion 104
5.4.1 Estimated FOH versus Actual FOH 104

vi

5.4.2 Degree of Suspension 104
5.4.3 Apportionment for Concurrent Delays 105
5.4.4 Float Ownership 106
5.4.5 Statistical Implications 107
5.4.6 Difficulties in Using the Proposed Method 108
5.5 Summary 109
Chapter 6 111
Novel Forensic Schedule Analysis Technique 111
6.1 Introduction 111
6.2 Issues in Forensic Schedule Analysis 113
6.2.1 Float and Float Ownership 113
6.2.2 Hard Logic vs. Soft Logic 117
6.2.3 Resource Allocation 118
6.2.4 The Dynamics of Float, Logic, and Resource Allocation 119
6.3 Novel Forensic Schedule Analysis Technique 120
6.4 Case Study 124
6.4.1 Day 2: One-Day Contractor-Caused Delay on Activity A 125
6.4.2 Day 4: One-Day Owner-Caused Delay on Activity B 127
6.4.3 Day 5: One-Day Concurrent Delays, Contractor- and Owner-Caused, on
Activities B and C 128
6.4.4 Day 6: One-Day Concurrent Delays, Owner- and Contractor-Caused, on
Activities C and D 130
6.4.5 Days 7 and 8: Two-Day Third Party-Caused Delay on Activity D 131
vii

6.4.6 Days 10 and 11: Two-Day Owner-Caused Delays on Activities E and G 132
6.5 Discussion 134
6.6 Summary 137

Chapter 7 139
Integrated Framework of Schedule and Damage Analyses 139
7.1 Introduction 139
7.2 Framework Description 140
7.3 Case Study 142
7.3.1. Applications of the New Framework to a Case Study 142
7.3.2 Discussion 145
7.4 Summary 145
Chapter 8 146
Conclusions and Recommendations 146
8.1 Conclusions and Contributions 146
8.1.1 The Effect of Resource Allocation on Forensic Schedule Analysis 146
8.1.2 The Enhanced Schedule Window Analysis Technique 147
8.1.3 ASAP as a New Approach for Quantifying Field Overhead Damages 147
8.1.4 FLORA as a Novel Forensic Schedule Analysis Technique 148
8.1.5 New Integrated Framework for Analyzing Schedule Delays and Damages 149
8.2 Recommendations 150
8.2.1 Schedule Analysis Considering Resource Allocation 150
8.2.2 Schedule Analysis Capturing the Dynamics of Float, Logic, and Resource
Allocation 150
viii

8.2.3 The Context of a Delay Addressed in Calculating Delay Damages 151
8.2.4 Apportionment for Concurrent Delays 151
8.2.5 Applications of ASAP and FLORA in the Industry 152
8.3 Limitations and Future Research 152
References 155

ix

List of Figures

Figure 1.1 Extended “triad of proof” in delay claims 6
Figure 2.1 Delay versus acceleration 20
Figure 2.2 Delays: responsibility, liability and recoverability 24
Figure 2.3 Delay concurrency scenarios 27
Figure 2.4 Generic methodology for analyzing delay claims 38
Figure 2.5 Mapping of forensic schedule analysis techniques 40
Figure 2.6 As-planned vs. as-built method 42
Figure 2.7 Contractor’s cost breakdown structure 52
Figure 2.8 Application areas of percentage markup versus Eichleay formula 61
Figure 3.1 Research framework 64
Figure 3.2 Types of effort and overhead costs 69
Figure 3.3 Contactor’s overhead costs 70
Figure 4.1. Schedules of the motivating example 74
Figure 4.2. As-planned resource-constrained schedule 79
Figure 4.3. Hypothesized as-built schedule 80
Figure 4.4. Traditional window analysis: window #1 81
Figure 4.5. Enhanced window analysis: window #1 82
Figure 4.6. Traditional window analysis: window #2 83
Figure 5.1. The context of delays versus delay responsibility 92
Figure 5.2. As-planned schedule 99
x

Figure 5.3. As-built schedule 100
Figure 5.4. Time plot for time-related field overhead versus week 103
Figure 5.5. Histogram of per-week time-related field overhead 108
Figure 6.1. The dynamics of float, logic, and resource allocation 115
Figure 6.2. FLORA process flowchart for “real-time” analysis 123
Figure 6.3. As-planned schedule 124

Figure 6.4. Analyses for the contractor-caused delay on activity A at day 2 126
Figure 6.5. Analysis for the owner-caused delay on activity B at day 4 128
Figure 6.6. Analysis for concurrent delays on B and C at day 5 129
Figure 6.7. Analysis for concurrent delays on C and D at day 6 130
Figure 6.8. Analysis for the third party-caused delay on D at days 7 and 8 131
Figure 6.9. Analyses for the owner-caused delays on E and G at days 10 and 11 132
Figure 7.1. Integrated framework for schedule and damages analyses 141

xi

List of Tables

Table 2.1 Divergent and inconsistent perspectives on concurrent delays 29
Table 2.2 Comparative results of schedule analysis methods 48
Table 2.3 Formulas for calculating home office overhead 56
Table 2.4 Allowed markup for home office overhead 59
Table 3.1 Criteria for evaluating forensic schedule analysis techniques 70
Table 4.1. Step-by-step schedule window analysis 76
Table 4.2. Schedule analysis summary 84
Table 5.1. ASAP’s steps for quantifying field overhead damages 97
Table 5.2. Project cost estimate (in dollars) 99
Table 5.3. Distributed activity-specific field overhead (in dollars) 102
Table 5.4. Field overhead delay damages (in dollars) 103
Table 6.1. FLORA’s rules for time impact analysis 121
Table 6.2. Delay events and their secondary effects 125
Table 6.3. Summary of forensic schedule analysis 134
Table 7.1. Activity-specific allocation of field overhead (in dollars) 143
Table 7.2. Field overhead delay damages (in dollars) under different methods 144

xii

Acknowledgements


I would like to thank many people for helping me during my graduate study and doctoral
research at Cal. I would particularly like to thank my research advisor, Professor William
Ibbs, for his invaluable guidance. He has advised me to research practical and interesting
areas. He also took a lead in securing my graduate assistantship in the last few years. I
am truly appreciative for the constructive comments of the other dissertation committee
members, Professors Glenn Ballard, Frederick Collignon, and Arpad Horvath. I would
also like to thank Professors Sara Beckman and Iris Tommelein for their exceptional
critiques and suggestions before and during my qualifying exam.
I extend many thanks to my sponsor, officers, friends, and colleagues. I owe a
special note of gratitude to VEF for financially supporting me in the first two years in the
United States. I would like to express appreciation to E&PM students at Cal for our
valuable discussion and interaction. Among them, I especially thank Kofi Inkabi, Martin
Chandrawinata, Sebastien Humbert, Tai-Lin Huang, Ying-Yi Chih, and Zofia
Rybkowski. I am very grateful for the generous support of the CEE Department staff,
especially Ms. Shelley Okimoto. I would also like to thank my Vietnamese seniors and
friends in Berkeley and the United States I have had opportunities to chat, play, and share
with my personal and professional hobbies, feelings, failures, and successes.
I would like to express my thanks to my former professors, teachers, and friends,
especially Professor Stephen Ogunlana, Do Thi Xuan Lan, Luu Truong Van, and Nguyen
Thi Dung. They continually stimulate my self-confidence even when I left them. I
xiii

would like to thank Dung for her lovely patience and sharing for many ups and downs of
our love over the past seven years. Though I do not have her anymore, I hope she is
always happy.
Finally, I would like to thank my family. I am especially grateful to my parents

for their eternal sacrifice. I always miss and love you, Mom. Even you no longer live in
this world to see your son growing up, I wish you and Anh Quyen are happy in the
heaven. We never forget your smiles, Anh Quyen. Special thanks to Anh Quang for his
endless support to our home and family. I wish you all have happy and wonderful lives.


xiv

Abbreviations


AACEI : The Association for the Advancement of Cost Engineering
ASAP : Activity-specific overhead allocation process
ASBCA : The Armed Services Board of Contract Appeals
BCA : Board of Contract Appeals
CDM : Continuous delay measurement
CPAT : Contemporaneous period analysis technique
CPM : Critical path method
C/SCSC : Cost/Schedule Control Systems Criteria
DDV : Daily delay values
DOD : The U.S Department of Defense
DOT : The Departments of Transportation
EBCA : The Department of Energy Board of Contract Appeals
EFC : Early finish cost
ENG BCA : The Army Corps of Engineers Board of Contract Appeals
EVA : Earned Value Analysis
EVMS : The earned value management system
FLORA : A new forensic schedule analysis technique
FOH : Field office overhead
FS : Finish-Start

G&A : General and administrative expense
xv

GSBCA : The General Services Board of Contract Appeals
HOOH : Home office overhead
IDT : Isolated delay type
JLARC : The Joint Legislative Audit and Review Commission
LFC : Late finish cost
LOE : Level of effort
NCHRP : National Cooperative Highway Research Program
P3 : Primavera Project Planner
SS : Start-Start
TIA : Time impact analysis
TRB : Transportation Research Board
VABCA : The Veterans Affairs Board of Contract Appeals

xvi

Symbols


ATF : Allowable total float
Ba : Total billings for actual contract period
Bc : Contract billings
Be : Contract billings for extended period
Bo : Total billings for original contract period
CD : Cost driver value for the whole contract
CD
i
: Cost driver value for activity i

D
i
: Duration of activity i
Da : Actual days of contract performance
De : Days of owner-caused delay
Do : Original days of contract performance
DD
j
: The delay day(s) for the j
th
analysis
DP : Delay period identified by a window analysis
(DP)
Wj
: Delay period of window W
j

∆TF : Difference in total float that an activity has after and before the
occurrence of the corresponding event and analysis
FOH : Field overhead
FOH
n
: Non-time-related field overhead
FOH
n
i
: Non-time-related field overhead for activity i
FOH
t
: Time-related field overhead

xvii

FOH
t
i
: Time-related field overhead for activity i
FOH
C
: Total compensable field overhead damages
(FOH
C
)
Wj
: Compensable field overhead damages in window Wj
HOOH : Home office overhead
i : i
th
activity or activity i
iD : Critically delayed activity i
iDo : Owner-caused critically delayed activity i
La : Total labor costs: actual period
Ld : Labor costs: delay period
Ma : Actual HOOH: entire period (%)
Me : Actual HOOH: delay period (%)
Mn : Normal HOOH (%)
Mp : Planned HOOH and profits at time of bid
OH : Overhead
Oa : Total overhead during actual contract period
Oc : Overhead allocable to contract
Oo : Total overhead during original contract period

PDD : The number of days that the party delays on the affected activity path
Rd : Daily overhead allocable to contract
RDD : The number of delayed days that a party is held responsible
TDD : The total delayed days of the entire project
TF : Total float
TF
C
: Contractor’s total float
xviii

TF
O
: Owner’s total float
uFOH
n
i
: Non-time-related field overhead for activity i per time unit
uFOH
t
i
: Time-related field overhead for activity i per time unit
uFOH
t
iD
: Time-related field overhead for critically delayed activity i per time unit
uFOH
t
iDo
: Time-related field overhead for owner-caused critically delayed activity i
per time unit

Vo : Original contract value
Wj : j
th

window period or window j
1

Chapter 1
Introduction


“Time is of the essence.
1
”
1.1 Background
Project schedules are invariably dynamic and uncertain. Various controllable and
uncontrollable factors can adversely affect the project schedule and cause delays. These
delays undoubtedly create negative impacts on project performance. They are also the
major cause of construction claims
2
(Hester et al., 1991; Abdul-Rahman et al., 2006).
Together with the money associated with increased costs and expenses for delays on a
project, delay claims are possibly the most problematic type of construction dispute case
to handle (Hughes, 2003a). As a result, forensic schedule analysis
3
or the identification
and analysis of delays become essential (Finke, 1999). They are however onerous tasks.
Contractors are prone to view most delays as the responsibility of the owner while
owners frequently attempt to tag delays as contractor-caused, third party-caused or
concurrent (Zack, 2001). Consequently, delays may lead to some form of dispute

resolution alternatives, from negotiation to litigation, which may be expensive and a

1
A proverbial expression
2
Claims in this context are defined as the seeking of consideration or change, or both, by one of the parties
to a contract based upon an implied or expressed contract provision (Diekmann and Nelson, 1985).
3
“Forensic scheduling analysis refers to the study and investigation of events using CPM or other
recognized schedule calculation methods for potential use in a legal proceeding” (AACEI, 2007).


2

crapshoot. There is a recent increase in both the number and size of construction claims
(Schone, 1985; Pinnell, 1998).

In addition to evaluating and apportioning responsibility for schedule delays, the
quantification of the damages caused by delays is also an extremely challenging job.
Most professionals agree that measuring and demonstrating evidence on the damages are
the most arduous part of many delay claims and construction cases (Overcash and Harris,
2005). All parties more consider the cost of delay and impact, are more sophisticated in
their scheduling techniques and tools, have tighter budgets that cannot afford delay or
impact, and are more contentious (Pinnell, 1992). As such, more appropriate approaches
for the analysis and determination of schedule delays and associated financial
consequences are imperative in today’s “claims-oriented” construction business.
1.2 The eed for Research
The fact that the construction industry is unable to properly address scheduling and delay
problems has led to a “chronically sick building industry” (Sweet and Schneier, 2004). In
addition, “most public and private construction contract disputes touch on the issue of

delay” (Calkins, 2006). Responding to such a challenge, practitioners and researchers
have created and employed many schedule analysis techniques. The level of
acceptability of each technique depends on its credibility and the court or board ruling the
corresponding delay claims. However, schedule-related issues such as float, float
ownership, soft logic, and resource allocation can cause delays yet their effects are
typically neglected in those techniques. For instance although a number of studies have