Literature on Construction Delay Analysis

Books 

Birkby, G. & Brough, P. (1999), Extensions of Time Explained , RIBA Publications Publications Ltd., London, UK.

The authors consider the wording of typical clauses in the most commonly used forms of building contract, examines relevant case law and provides a step-by-step guide for the assessment of delays. They also give guidance on problems one might encounter in dealing with extensions of time.

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Birkby, G., Ponte, A. & Alderson, F. (2008), Good Practice Guide: Extensions of Time , RIBA Publications Ltd., London, UK.

This is a straight forward jargon-free practical guide about all aspects of extensions of time for all construction industry professionals. professionals.  An extension of time time is an issue issue which most most architects and other construction construction professionals professionals face sooner sooner or later in their their career. It is a complex area where the professional administering the contract must act in accordance with the contract conditions andfailure to do so will potentially land the professional and/or his client in court. Throughout the guide the information is presented in a way that is immediately accessible, useful and related to the latest JCT Contracts. Tables, graphs and a glossary are used to help the reader navigate through chapters on liquidated damages, terms under  standard contracts, notification of delay, supply of information, assessment, concurrent delays and ethical issues. The authors have clarified potentially complex issues with short, relevant examples drawn from case law and have defined difficult concepts in easy-reference text boxes. This Good Practice Guide  is a friendly reference tool for all architects or other professionals charged with assessing extensions of time.

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Bramble, B. & Callahan, Callahan, M. (2010), Construction Delay Claims (4 th  Ed.), Aspen Publishers, New York, USA.

Contracts can be your first line of defense against delays. But they have to be drafted very carefully. Construction Delay Claims gives you an in-depth analysis of all the pertinent clauses and details what they can and can t do to minimize delays and avoid litigation.

Construction Delay Claims, Fourth Edition , by Barry B. Bramble and Michael T. Callahan is written for everyone involved with delay and impact construction claims the most common form of disputes in the construction industry. You ll find that t his resource presents the most thorough, detailed review of delay claims liability available, including a complete description of the entire process for filing and pursuing claims along with more than 1,950 cases and analyses. Construction Delay Claims gives you the information you need to determine your best course of action. The book presents detailed knowledge drawn drawn from t he authors thirty-five years of experience in the industry. You ll learn how to anticipate delays and mitigate damages through the use of advanced planning and immediate responses by the parties involved. You ll also receive helpful instructions about the best use of construction schedules schedules to avert delays, or to prove their impact if they do occur. Construction Delay Claims keeps you completely up-to-date with the changes in the construction industry, industry, and the construction litigation process. Coverage includes:  Effective ways to challenge a claimant s use of the Total Cost Method of Calculation

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The effectiveness of no damages for delay clauses

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The use of ADR methods to resolve delay claims

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The meaning and implication of concurrent delays

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Cumulative impact effect of multiple change orders

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The impact and probability of delays in design-build, construction management, management, and multiple prime contracting

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Latest research into the effect and measurement of lost productivity

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The most recent assessments of how states are applying the Eichleay  formula

Carnell, N. J. (2005), Causation and Delay in Construction Disputes (2 nd  Ed.), Blackwell Publishing Ltd., Oxford, UK.

Construction claims claims frequently involve a dispute about delay. Whether or not the c ontractor or client has a claim which can be proved successfully depends on establishing establishing causation and understanding legal rights and obligations. This book shows how to identify and avoid problems during the project, and analyses claims for delay. The new edition takes account of case law since 1999 and has new sections on adjudication, risk allocation and the Delay and Disruption Protocol.

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Chappell, Chappell, D. (2011), Building Contract Claims (5 th  Ed.), Blackwell Publishing Ltd., Oxford, UK.

Many building projects are the subject of claims – claims  – the assertion of a right, usually by the contractor, to an extension of t he contract period or an additional payment under the terms of the building contract. Many of these claims are unsound or ill –founded,  –founded, often because the basic principles are misunderstood. This highly regarded regarded book examines the legal basis of claims for extensions of time

and additional payment, and what can and cannot be claimed under the main forms of contract. It includes chapters dealing with direct loss and expense, liquidated damages, extension of time, concurrency problems, acceleration, time at large, common law and contractual claims, global claims, and heads of claim and their substantiation. With the publication of the fifth edition, Building Contract Claims has been thoroughly revised to ensure it is fully up to date with the latest contracts, court judgments and building p ractice. Changes include: Coverage of over 60 additional relevant court cases Coverage of the 2005 JCT contracts suite Coverage of changes to the NEC contract Coverage of additional contracts such as Constructing Excellence; Measured Term Contract and the ACA PPC2000 contract together with the 2005 relevant JCT sub –contracts Important changes to liquidated damages and to extensions of  time, and the giving of notices Appendix 1 has been substantially revised Like its predecessors, the fifth edition of Building Contract Claims will be essential reading for architects, contract administrators, project managers and quantity surveyors, as well as contractors, contracts consultants and construction lawyers. 

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Davison, R. & Mullen, J. (2009), Evaluating Contracts Claims (2 nd  Ed.), Blackwell Publishing Ltd., Oxford, UK. Eggleston, B. (2009), Liquidated Damages and Extensions of Time: In Construction Contracts  (3 rd  Ed.), Blackwell Publishing Ltd., Oxford, UK.

Liquidated damages and extensions of time are complex subjects, frequently forming the basis of contract claims made under the standard building and civil engineering contracts. Previous editions of Liquidated Damages and Extensions of Time are highly regarded as a guide for both construction industry professionals and lawyers to this complex area. The law on time and damages continues to develop with an increasing flow of judgments from the courts. Alongside this, the standard forms of contract have also developed over time to reflect prevailing approaches to contractual relationships. Against this background a third edition will be welcomed by construction professionals and lawyers alike. Retaining the overall approach of the previous editions, the author clarifies, in a highly readable but legally rigorous way, the many misunderstandings on time and damages which abound in the construction industry. The third edition takes account of a large volume of new case law since the previous edition was published over ten years ago, includes a new chapter on delay analysis and features significantly expanded chapters on penalty clauses, the effects of conditions precedent and time-bars, and the complexities of causation.

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Gibson, R. (2008), Construction Delays: Extensions of Time and Prolongation Claims , Taylor & Francis, New York, USA.

This book provides guidance on delay analysis, particularly in relation to extension of time submissions. It gives readers the information and practical details to be considered in formulating and resolving extension of time submissions and time -related prolongation claims. Useful guidance and recommended good practice is given on all t he common delay analysis techniques, and worked examples of  extension of time submissions and time-related prolongation claims are included. Written in a practical and user-friendly style, the book includes helpful charts and graphics. It will be useful f or construction professionals dealing with extensions of time and delay claims, and for lawyers and others who are involved in the contentious side of the construction and engineering industries.

Roger Gibson has over 40 years of planning & programming experience in the construction and engineering industries. During the latter  part of his career his has received many appointments as an Expert in time-related disputes.

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Haidar, A. & Barnes, P. (2011), Delay and Disruption Claims in Construction: A practical  approach, Institution of Civil Engineers, London, UK.

The aim of the book is to provide readers with the practical knowledge, in a legal, contractual and technical framework, for  understanding and preparing delay and disruption claims in the construction industry and to provide calculation methodologies for  damages and mitigation mechanisms. This practical guide describes issues such as contractual obligations, how to write delay and disruption claims, legal reasoning behind validating claims, and the application of Critical Path Methods to calculate time delays and damages. The techniques discussed in the book can be used on projects of any size, under all forms of construction contract, and are applicable internationally. 

Keane, P. J. & Caletka, A. F. (2008), Delay Analysis in Construction Contracts , Blackwell Publishing Ltd., Oxford, UK.

The most significant unanticipated costs on many construction projects are the financial impacts associated with delay and disruption to the works. Assessing these, and establishing a causal link from each delay event to its effect, contractual liability and the damages experienced as a direct result of each event, can be difficult and complex. This book is a practical guide to the process of delay analysis and includes an in-depth review of the primary methods of delay analysis, together with the assumptions that underlie the precise calculations required in any quantitative delay analysis. The techniques discussed can be used on projects of any size, under all forms of construction contract, both domestic and international. The authors discuss not only delay analysis techniques, but also their appropriateness under given circumstances, demonstrating how combined approaches may be applied where necessary. They also consider problematic issues including 'who owns the float', concurrent delay, early completion programmes, and disruption. The book, which is well illustrated, features practical worked examples and case studies demonstrating the techniques commonly used by experienced practitioners.

This is an invaluable resource to contractors, architects, engineers, surveyors, programmers and delay analysts, and will also be of  interest to clients' professional advisors managing extension of time or delay claims, as well as construction lawyers who require a better understanding of the underlying assumptions on which many quantitative delay analyses are based.

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Knowles, R. (2005), 150 Contractual Problems and Their Solutions (2 nd  Ed.), Blackwell Publishing Ltd., Oxford, UK.

This book considers 150 problems that regularly arise in building contracts and provides a detailed explanation as to their answers. It cites key parts of legal decisions as authority. The new edition includes some 50 new problems, and r evised solutions to a third of the problems to take account of recent case law.

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Lowsley, S. & Linnett, C. (2006), About Time: Delay Analysis in Construction , Royal Institution of Chartered Surveyors, London, UK.

Construction projects frequently suffer from delays. For years construction industry professionals have struggled to unravel the causes and assess periods of delays without the assistance of up -to-date practical advice on the subject - until now.  About Time provides a straightforward reference for everyone working in the building and civil engineering industry who needs to understand delay claims. It c ontains clear explanations of: - various forms of construction programming techniques - how to monitor and record progress - how to analyse delays - strengths and weaknesses of the different techniques - requirements of the main standard forms of contract - key English case law concerning construction delay claims - different means of resolving disputes This book is written in simple English, free from acronyms and programmers' jargon, and tackles the difficulties of delay analysis head on. As a result About Time strips away the mystique surrounding the subject of delay analysis and reveals the limitations of the various methods of delay analysis commonly used. The Authors: Stephen Lowsley MSc MAPM is a Consultant Programmer. He spends much of his time carrying out retrospective delay analysis of  construction projects for contractors and employers. He has acted as an expert witness in arbitration and litigation and has also directly assisted arbitrators and adjudicators in the assessment of delay claims. Christopher Linnett BSc DipArb FRICS FCIArb is a Chartered Quantity Surveyor who regularly acts as an adjudicator, expert witness, arbitrator and advisor. He is also a visiting tutor and examiner on the postgraduate Diploma in Arbitration course at the College of Estate Management, Reading. Contents: 1 The construction industry's propensity for delays 2 Planning for the project 3 Planning techniques 4 Monitoring progress 5 Analysis of delay 6 Preparing and evaluating a claim 7 Standard forms of contract 8 Case law and delay 9 Dispute resolution 

SCL (2002), The Society of Construction Law Delay and Disruption Protocol , The Society of  Construction Law, Wantage, UK.

This Protocol has been prepared by the Society of Construction Law for determining extensions of time and compensation for delay and disruption. Published on October 16th 2002, It exists to provide guidance to all parties to the construction process when dealing with time/delay matters. It recognises that transparency of information and methodology is central to both dispute prevention and dispute resolution.

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Trauner, T. et al (2009), Construction Delays: Understanding Them Clearly, Analyzing Them  Correctly (2 nd  Ed.), Butterworth-Heinemann, London, UK.

Delays in construction projects are frequently expensive, since there is usually a construction loan involved which charges interest, management staff dedicated to the project whose costs are time dependent, and ongoing inflation in wage and material prices. Many techniques are used to analyze delays. Some of these methods have inherent weaknesses and should be avoided. This book points out the shortcomings of these faulty methods and explains how a delay analysis should be performed. It then describes specifically how the analysis is done with CPM schedules. A explanation of delays and delay damages, presented in a straightforward, accessible manner, should be useful to public and private owners, construction managers, general contractors, subcontractors, designers, suppliers, and

attorneys whose work involves them in the construction industry. The discussion will include subtleties of the process, such as shifts in the critical path, and non-critical delays. The subject of damages is covered in detail, including the major categories of extended field overhead and unabsorbed home office overhead. Likewise, the damages suffered by the owner, either actual or liquidated, are also explained. Finally, a chapter is devoted to managing the risk of delays and time extensions from the viewpoints of the various parties to a construction project. A discussion of early completion schedules and constructive acceleration is also included. In this new ediion, all chapters are updated to reflect the changes in the construction field since the first edition published over l6 years ago. The 2nd edition includs over 40% more information such as new methods for analyzing delays with examples of the proper  approach. The author also includes a new chapter on risk managment which focuses on the delay-related risks of the various parties in a construction project. Explains the different categories of delays  Addresses the concept of concurrency and also non-critical delays Discusses the more common approaches used f or measuring and analyzing delays and the strengths and weaknesses associated with them Prevention of Time-Related Delay Problems

Journal Articles 

Akinsola, A., Potts, K., Ndekugri, I. & Harris, F. (1997), ―Identification and evaluation of factors influencing variations on building projects‖, International Journal of Project Management , Vol. 15, No. 4, pp. 263-267.

This paper identifies and quantitatively examines factors influencing the magnitude and frequency of variations on building projects. The evaluation was based on the analysis of 46 completed building projects in the UK. The identified factors were classified into four main categories: client characteristics, project characteristics, project organization and environmental factors. The findings of the study suggest that there is a relationship between these factors and the magnitude and frequency of variations. Adequate attention given to these significant factors at pre- and post-tender stages of the project should reduce the effect of variations. 

Alkass, S., Mazerolle, M., Trabaldos, E. & Harris, F. (1995), ―Computer aided construction delay analysis and claims preparation‖, Construction Management and Economics , Vol. 13, No. 4, pp. 335-352.

Delays are the most common and costly problem encountered on construction projects. Analysing construction delays has become an integral part of the project's construction life. To prepare for litigation, schedule documentation proving responsibility must be prepared. With present methods of tracking projects, the preparation of such schedules can be time consuming and costly. The analysis itself is usually complex and can be aided by a computerized approach. This paper describes the introduction of a computer system for delays claim analysis called computerized delay claims analysis (CDCA). The system utilizes the isolated delay type (IDT) technique. Part of  this system can use existing software such as project management, cost control, database management and spreadsheets. In addition to these, an expert system tailored to the specific expertise of construction claims has been used to facilitate the decision making process. CDCA is tested against a real case study of a building project to demonstrate its effectiveness in determining the responsibility of contracting parties with respect to the project's delays. The system is expected to assist in improving the process of delays analysis, thus reducing the cost of claims preparation. 

Alkass, S., Mazerolle, M. & Harris, F. (1996), ―Construction delay analysis techniques‖, Construction Management and Economics , Vol. 14, No. 5, pp. 375-394.

Construction projects continue to suffer delays. Things go wrong and the project's completion date gets pushed back, with someone to be blamed for it. In practice, attempts are made to identify the causes of delays and schedules are modified to incorporate revised duration and new project time. The analysis itself is usually complex and can be aided by a computerized approach. This paper  discusses different delay analysis techniques that are currently used by practitioners in the construction industry. It also discusses a proposed new delay analysis technique called the Isolated Delay Type (IDT). These techniques were tested against a case example and their strengths and weaknesses highlighted. The new technique can be used as a standalone module for delay analysis or could be incorporated within a computer system for construction delay analysis and claims preparation called Computerized Delay Claims  Analysis (CDCA) that integrates different software including an expert system and management software such as scheduling and a database or spreadsheet. 

Al-Kharashi, A. & Skitmore, M. (2009), ―Causes of delays in Saudi Arabian public sector  construction projects‖, Construction Management and Economics , Vol. 27, No. 1, pp. 3-23.

Many public construction projects have been undertaken throughout the Kingdom of Saudi Arabia as part of the government's national development plans in the past three decades, with significant public expenditure involved. One of the critical problems concerning these projects is the frequent and lengthy delays t hat occur. In order to improve the situation, it is first necessary to identify the major causes involved. Several studies have already been reported which do this but all use different sets of variables. Also, none has attempted to identify the extent to which improvements are possible in practice. A new survey is reported that uses all the variables from the previous work and measures for both current degree of effect on delays and the extent to which each can be practically improved. These are contained in seven groupings: client, contractor, consultant, materials, labour, contract and relationship‐related causes. The survey covers a sample of 86 clients, contractors and consultants working in the Saudi construction industry. The analysis reveals some considerable heterogeneity between the cause groupings and respondent groupings in terms of means and correlations, apparently partly due to lack of knowledge of respondents and a tendency for the consultants to blame the contractors for the delays and vice versa. The main results, therefore, are disaggregated to reflect the views of each respondent group concerning each group of causes. In general however, it is found that the most influencing current cause of delay is the lack of qualified and experienced personnel— attributed to the considerable amount of large, innovative, construction projects and associated current undersupply of manpo wer in the industry. 

Al-Momani, A.H. (2000), ―Construction delay: a quantitative analysis‖, International Journal of  Project Management , Vol. 18, No. 1, pp. 51 –59.

 Avoiding construction claims and disputes requires an understanding of the contractual terms and causes of claims. The dual underlying theme of this paper is to investigate the causes of delays on 130 public projects in Jordan and to aid construction managers in establishing adequate evaluation prior to the contract award using quantitative data. Projects investigated in this study included residential, office and administration buildings, school buildings, medical centers and communication facilities. Results of this study indicates the main causes of delay in construction of public projects relate to designers, user changes, weather, site conditions, late deliveries, economic conditions and increase in quantity. The presence of these factors have an impact on the successful completion of  the projects at the t ime contractually specified. The findings suggest that special attention to factors identified in this st udy will help industry practitioners in minimising the risk of contract disputes.

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Arditi, D. & Pattanakitchamroon, T. (2006), ―Selecting a delay analysis method in resolving construction claims‖, International Journal of Project Management , Vol. 24, No. 2, pp. 145-155.

Delays occur commonly in construction projects. Assessing the impact of delay is sometimes a contentious issue. Several delay analysis methods are available but no one m ethod can be universally used over another in all situations. The selection of the proper  analysis method depends upon a variety of factors including information available, time of analysis, capabilities of the meth odology, and time, funds and effort allocated to the analysis. The paper reviews 20 research studies that discuss various aspects of delay analysis methods and summarizes the advantages and disadvantages of widely used delay analysis methods, including the as -planned vs. asbuilt, impact as-planned, collapsed as-built, and time impact analysis methods. The paper also discusses the most important issues in delay analysis that affect the results of the analysis. The selection of a suitable analysis method depends heavily on the availability of  scheduling data, the familiarity of the analyst with the capabilities of the software used in the project, clear specifications in the contract concerning the treatment of concurrent delays and the ownership of float. 

 Arditi, D. & Pattanakitchamroon, T. (2008), ― Analysis Methods in Time-Based Claims‖, Journal  of Construction Engineering and Management , Vol. 134, No. 4, pp. 242-252. (cited 2 times)

 Assessing the impact of delay and resolving disputes are contentious issues since courts and administrative boards do not specify standard delay analysis practices. First, the advantages and disadvantages of widely used delay analysis methods, including the asplanned versus as-built, impact as-planned, collapsed as-built, time impact, and productivity analysis methods are summarized. Fiftyeight claim cases associated with time-based disputes in government work during the 1992 –2005 period are extracted and analyzed to observe issues in time-based claims, including the reasons why they occur and the common practices in their resolution. The effects of  various factors on the selection of a delay analysis method are examined. These factors include the type of schedule used, the schedule updating practice, the use of existing versus newly created schedules, and the availability of expertise, information, time, and funds. A project management system that makes use of regularly updated network schedules, and that maintains adequate project records should allow a scheduling expert to select a delay analysis method that would make a claim quite convincing. 

Assaf, S.A. & Al-Hejji, S. (2006), ―Causes of delay in large construction projects‖, International  Journal of Project Management , Vol. 24, No. 4, pp. 349-347.

 A survey on time performance of different types of construction projects in Saudi Arabia was conducted to determine the causes of  delay and their importance according to each of the project participants, i.e., the owner, consultant and the contractor. The field survey conducted included 23 contractors, 19 consultants, and 15 owners. Seventy-three causes of delay were identified during the research. 76% of the contractors and 56% of the consultants indicated that average of time overrun is between 10% and 30% of the origin al duration. The most common cause of delay identified by all the three parties is ―change order‖. Surveys concluded that 70% of projects experienced time overrun and found that 45 out of 76 projects considered were delayed. 

Bordoli, D. & Baldwin, A. (1998), ― A methodology for assessing construction project delays‖, Construction Management and Economics, Vol. 16, No. 3, pp. 327-337.

Different categories of delay and the different types of delay found on construction projects are identified. Existing methods for  assessing the effect of delaying events are reviewed and the results of an industry survey presented. None of t he commonly recognized methods for delay analysis allow the assessment of three important issues at t he same time: the progress of the project at the time the delay occurred; the changing nature of the critical path; and the effects of action taken (or that should have been taken) to minimize potential delays. A new method of delay analysis is presented. This method takes into consideration all these issues, and is a clear, straightforward step-by-step approach to the calculation of the expected delay in the completion of the project as a result of delays in activities encountered during the project. It uses a dynamic model considered by both experts and practitioners to be the best method to take account of progress and form the basis of delay claims. 

Braimah, N. & Ndekugri, I. (2008), ―Factors influencing the selection of delay analysis methodologies‖, International Journal of Project Management , Vol. 26, No. 8, pp. 789 –799.

Delays and disruption to contractors‘ progress are a major source of claims and disputes in the construction industry. Often at t he heart of the matter in dispute is the question of the extent of each contracting party‘s responsibility for the project delay. Various delayanalysis methodologies have been developed over the years as aids to answering this question. This paper reports on a study into the factors that influence analysts‘ selection from these methodologies. Eighteen factors were identified through literature review and pilot surveys and then ranked on their relative importance based on data collected in a nation-wide survey of UK construction organisations. Factor  analysis was used to reduce the factors into 6 group factors: project characteristics, contractual requirements, characteristics of ba seline programme, cost proportionality, timing of the analysis and record availability. 

Bubshait, A. & Cunningham, M. (1998), ―Comparison of Delay Analysis Methodologies‖, Journal of Construction Engineering and Management, Vol. 124, No. 4, pp. 315-322. (cited 13 times)

During a construction project, delays may result from many circumstances. Delays may be caused by the owner, the contractor, by acts of God, or a third party. They may occur early or late in the job, alone or with other delays. Negotiating a fair and timely damage settlement is beneficial to all parties. Network-based scheduling is an excellent vehicle f or negotiating settlement of changes, disputes, and delays throughout the project. In the construction industry, however, there is no single, standard, and ―accepted‖ procedure to determine the impact of schedule delays due to change orders or other unplanned developments. In this paper three delay

measurement processes were studied. These procedures were employed to measure delay impact, utilizing computerized critical path method (CPM) analyses, performed on genuine construction schedules. Results indicate that outcomes of delay analyses are not predictable, nor can one method be used universally. However, in given circumstances, one procedure can be more be neficial than another. Guidelines for the utilization of each method have been presented. 

Chan, D. & Kumaraswamy, M.M. (1997), ― A comparative study of causes of time overruns in Hong Kong construction projects‖, International Journal of Project Management , Vol. 15, No. 1, pp. 55-63.

This paper presents the results of a survey undertaken to determine and evaluate the relative importance of the significant factors causing delays in Hong Kong construction projects. The survey covered 83 previously identified delay factors, which were grouped into eight major categories. The main reasons for delays were analyzed and ranked according to different groups classified on the basis of  (a) the role of the parties in the local construction industry (i.e. whether clients, consultants or contractors) and (b) the type of projects. Results indicate that the five principal and common causes of delays are: ‗poor site management and supervision‘, ‗unforeseen ground conditions‘, ‗low speed of decision making involving all project teams‘, ‗client-initiated variations‘ and ‗necessary variations of works‘. Differing perceptions as to the principal causes delaying projects are observed between Hong Kong, Saudi Arabia and Nigeria, the two latter countries being chosen for purposes of comparison with other countries. It is hoped that the significant delay factors identified in this survey will provide a basis for strategies to minimize delays and will also be incorporated into a ‗construction time‘ f orecasting model for Hong Kong construction projects in the future research programme. 

Chester, M. & Hendrickson, C. (2005) ―Cost Impacts, Scheduling Impacts, and the Claims Process during Construction‖, Journal of Construction Engineering and Management, Vol. 131, No. 1, pp. 102-107. (cited 1 time)

Construction mismanagement results in multiple problems that can cascade throughout the work force chain, affecting the schedule and leading to damages to multiple parties. Although the problem may start with a single subcontractor, it can result in all contractors feeling some impact to their work. In this paper, a case study is presented of a project with seven different mismanagement scenarios. A description of each scenario is provided as well as a quantification of the damages that result f rom the problem. A construction claims section is also included that addresses many of the issues that could result from a claim for each of the seven scenarios. A discussion is presented outlining possible preventative steps to minimize the damages from the problems presented. 

Fan, S. (2012), ―Modified Time Impact Analysis Method‖, Journal of Construction Engineering  and Management , Vol. 138, No. 2, pp. 227-233. (cited 0 times)

Delay claims are a common occurrence in construction projects. Many techniques have been developed to assess these delays. The time impact technique is the preferred approach for resolving complex disputes that are related to delays and delay compensation. However, this approach is time-consuming and costly to operate. This research proposes a new approach, similar to the time impact technique, which evaluates delay events in chronological order. The details of the modified time impact analysis (MTIA) method are provided, along with one example to demonstrate its advantages. This method is significantly easier to prepare, and the results generated by this new approach are easier to discuss and examine. 

Faridi, A.S. & El-Sayegh, S.M. (2006), ―Significant factors causing delay in the UAE construction industry‖, Construction Management and Economics , Vol. 24, No. 11, pp. 11671176.

Construction delay is considered one of the most recurring problems in the construction industry. Delays have an adverse impact on project success in terms of time, cost, quality and safety. The effects of construction delays are not confined to the construction industry only, but influence the overall economy of a country like UAE, where construction plays a major role in its development and contributes 14% to the GDP. Thus, it is essential to define the most significant causes of delay in order to avoid or minimise their impact on construction projects. A detailed questionnaire was developed and used to get input from professionals associated with the UAE construction industry. The perspective of contractors and consultants has been analysed to rank the causes of delays based on their  Relative Importance Index. Contractors and consultants were in agreement on t he most significant causes of delays. The research revealed that 50% of the construction projects in UAE encounter delays and are not completed on time. The top 10 most significant causes of construction delays have been identified by this research. Approval of drawings, inadequate early planning and slowness of  the owners' decision‐making process are the top causes of delay in the UAE construction industry. 

Harris, R. & Scott, S. (2001), ―UK practice in dealing with claims for delay ‖, Engineering Construction and Architectural Management , Vol. 8, Nos. 5-6, pp. 317-324.

The paper describes four methods of dealing with delay claims that effectively sum up the main approaches to this problem that have been offered in the literature. This is then followed by a description and discussion of results from a new survey aimed at f inding out exactly how professionals in the UK construction industry approach these difficult issues. It appears that those who deal with delay claims in the UK are likely to use a critical path method network to do this and generally approve of a methodology that attempts to understand how well the contractor would have fared ‗but for‘ the existence of employer -responsible delays. There is less agreement about who should be said to own the float, but as is explained in the paper, it is possible for this matter to be dealt with by the insertion of a clause in the contract documents.

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Hegazy, T. & Zhang, K. (2005), ―Daily Windows Delay Analysis‖, Journal of Construction  Engineering and Management, Vol. 131, No. 5, pp. 505-512. (cited 10 times)

Critical path method delay analysis techniques are widely applied in the construction industry, with the windows method being regarded as technologically advantageous. The approach looks at different schedule snapshots (windows) throughout the project and analyzes the contractor versus owner responsibility for delaying the critical paths. Accordingly, decisions regarding time and/or cost compensation could be made. While the technique is beneficial, it is computationally intensive and produces different results with different window sizes. Commercial software provide little support in this regard and the analysis is usually done manually. In this paper, a m odified windows approach is introduced with computerized daily analysis of delays so that accurate and repeatable results are produced. The new approach is coupled with a new representation of progress information and is readily usable by professionals and researchers to evaluate project delays. Details of the daily analysis are introduced along with two case studies that demonstrate its advantages over  the traditional windows approach. A downloadable version is made available for experimental use by researchers and professionals. 

Hegazy, T. & Menesi, W. (2008), ―Delay Analysis under Multiple Baseline Updates‖, Journal of  Construction Engineering and Management, Vol. 134, No. 8, pp. 575-582. (cited 3 times)

Windows delay analysis has been recognized as one of the most credible techniques for analyzing construction delays. To overcome some of the drawbacks of windows delay analysis, this paper introduces improvements to a computerized schedule analysis model so that it will produce accurate and repeatable results. The model considers multiple baseline updates due to changes in the durations of  the activities and the logical relationships among them, as well as the impact of resource overallocation. The model uses a daily window size in order to consider all fluctuations in t he critical path(s) and uses a legible representation of progress information to accurately apportion delays and accelerations among project parties. A simple case study has been implemented t o demonstrate the accuracy and usefulness of the proposed delay analysis model. This research is useful for both researchers and practitioners and allows detailed and repeatable analysis of the progress of a construction project in order to facilitate corrective actions and claim analysis. 

Hegazy, T. & Menesi, W. (2010), ―Critical Path Segments Scheduling Technique‖, Journal of  Construction Engineering and Management, Vol. 136, No. 10, pp. 1078-1085. (cited 1 time)

While the critical path method (CPM) has been useful f or scheduling construction projects, years of practice and research have highlighted serious drawbacks that hinder its use as a decision support tool. This paper argues that many of CPM drawbacks st em from the rough level of detail at which the analysis is conducted, where activities‘ durations are considered as continuous blocks of time. The paper thus proposes a new critical path segments (CPS) mechanism with a finer level of granularity by decomposing the duration of  each activity into separate time segments. Three cases are used to prove the benefits of using separate time segments in avoiding complex network relationships, accurately identifying all critical path fluctuation, better allocation of lim ited resources, avoiding multiplecalendar problems, and accurate analysis of project delays. The paper discusses the proposed CPS mechanism and comments on several issues related to its calculation complexity, its impact on existing procedures, and future extensions. This research is more beneficial to researchers and has the potential to revolutionize scheduling computations to resolve CPM drawbacks. 

Ibbs, W. & Nguyen, L.D. (2007), ―Schedule Analysis under the Effect of Resource Allocation‖, Journal of Construction Engineering and Management, Vol. 133, No. 2, pp. 131-138. (cited 5 times)

The construction industry has employed various schedule analysis techniques to support delay claims. Paradoxically, resource-related issues are frequently ignored even though they can affect project completion time, too. The research presented here shows that delay analysis without resource allocation practice substantially affects results of schedule analysis. Some delay can cause unrealistic resource allocation in downstream work, which in turn m ay further delay the project. The effect of resource allocation can either add to or reduce the severity of some delaying event. Apportionment of delay responsibility may be inaccurate unless resource allocation practice is considered in the analysis. Practical and necessary steps are proposed to enhance the existing window analysis technique. A case study is presented to compare the enhanced window analysis with the existing window analysis. This research enables practitioners to make delay analyses and claims more practical and reliable. Further studies are needed to improve the usability, credibility, and acceptability of schedule analysis considering resource allocation. 

Ibbs, W., Nguyen, L.D. & Simonian, L. (2011), ―Concurr ent Delays and Apportionment of  Damages‖, Journal of Construction Engineering and Management, Vol. 137, No. 2, pp. 119126. (cited 0 times)

This paper focuses on the subject of concurrent delay from a general contractor (GC)-subcontractor perspective. When there is a concurrent delay by multiple subcontractors, or between the GC and other subcontractor(s), there has not been a uniform approach as to how the liquidated damages are apportioned. Previous research seems to ignore this issue. This paper first reviews some relevant court cases. Using a warehouse project as a case study, it then examines different practices that the GC could take in apportioning

damages of concurrent delays to both himself/herself as well as to the responsible subcontractors. Results are very inconsistent between and within the apportionment practices. This supports an alternative hypothesis that apportionment is an important issue. Practitioners should specify which apportionment practice will be used and under what circumstances it will be applied in their  subcontracts. Researchers may develop a more consistent and reliable approach f or this type of apportionment. 

Kartam, S. (1999), ―Generic Methodology for Analyzing Delay Claims ‖, Journal of Construction  Engineering and Management, Vol. 125, No. 6, pp. 409-419 (cited 10 times)

It is common for a construction project to encounter delays. There are several reasons that can contribute to delaying a project.  Analyzing the various causes that contribute to a project's delay is an important task to resolving it. Determining, in a scientific manner, the impact, timing, and the contributing effect of each of those causes to the overall delay should assist in helping the parties settle the delay without litigation. Project participants are becoming more aware of the high costs and risks associated with delay claims and their  litigation. Thus, the construction industry needs to develop methodologies and techniques to prevent and more efficiently resolve delay claims. While many practitioners have been following some kind of a m ethodology for analyzing delay claims, a written exposition of  such a methodology is not widely available in the literature. Thus, this paper presents a written exposition of a generic methodology for  analyzing delay claims. This methodology has been developed and successfully used, by the writer, in various projects to reso lve delay claims. The developed methodology will be illustrated through its application in those projects. Moreover, this methodology shows that while there are several techniques for analyzing delay claims, very few of these can be considered adequate. The use of such an adequate technique is a key in obtaining a fair allocation of the delay responsibility. This paper's methodology utilizes one of these few adequate techniques for analyzing delay claims. 

Kim, Y., Kim, K. & Shin, D. (2005), ―Delay Analysis Method Using Delay Section‖ , Journal of  Construction Engineering and Management, Vol. 131, No. 11, pp 1155-1164. (cited 3 times)

The most common cause of construction claims is delay. Moreover, delay claims are often extremely complex and difficult to resolve. For this reason, the construction industry requires an effective and reliable method for analyzing the causes and effects of construction delay. Presently, the methods of analysis in common use do not adequately account for several commonly encountered situations. As a result, project time extensions are often considered without rigorous analysis. Therefore the objective of this study is to propose a nd describe an effective and logical method for evaluating construction delays that adequately accounts for commonly encountered situations. To achieve this objective, the writers propose a new methodology called ―delay analysis method using delay section‖ (DAMUDS) as a means of overcoming two limitations of existing methods: (1) inadequate accounting of concurrent delay and (2) inadequate accounting of time-shortened activities. The DAMUDS method builds upon the widely used m ethod of contemporaneous period analysis. The writers‘ points are illustrated through the use of an example case. 

Kraiem, Z. & Diekmann, J. (1987), ―Concurrent Delays in Construction Projects‖, Journal of  Construction Engineering and Management, Vol. 113, No. 4, pp 1155-1164. (cited 24 times)

The time allowed for construction project performance is usually an important consideration for both the project owner and the project contractor. Yet, it is typical for construction projects to be delayed. Delays may be caused by the owner (compensable delay), by the contractor (nonexcusable delay), by acts of god, or a third party (excusable delay), or several different kinds of delays may happen concurrently. Because of the many sources and causes of construction delays, it is often difficult to analyze the ultimate liability in delay claims. The original schedule (as ‐planned) is known, and, likewise, the actual schedule (as‐built) is known. What is unknown is the appropriate schedule when all allowable adjustments to the schedule are taken into account; this schedule is often called the as‐adjusted schedule. This paper presents a tool to aid in analysis of delay claims. The procedure set forth will handle delays and accelerations and will help in determination of the as‐adjusted schedule. 

Kumaraswamy, M.M. & Yogeswaran, K. (2003), ―Substantiation and assessment of claims f or  extensions of time‖, International Journal of Project Management , Vol. 21, No. 1, pp. 27-38.

Standard forms of contract provide for extensions of time (EOT) due to excusable delays, and EOT claims are common in many construction projects. The contractor and the supervising engineer often spend considerable time on substantiating and assessing such claims. However, a variety of diverse techniques have been employed for such evaluations. A study was undertaken to analyse d ifferent EOT evaluation techniques in Hong Kong, which continues to be a hotbed of construction activity attracting international organisations. Reasons for delays in the submission and assessment of EOT were also probed. Conclusions on the suitability of different techniques are drawn from an analysis of both the literature reviewed and a consolidation of practitioner perceptions, as derived from a questionnaire survey and subsequent in-depth interviews. This leads to recommendations for explicit policies, clear guidelines, tool-kits and improved contractual procedures that will upgrade the management of this crucial area. 

Lee, H., Ryu, H., Yu, J., & Kim, J. (2005), ―Method for Calculating Schedule Delay Considering Lost Productivity‖, Journal of Construction Engineering and Management , Vol. 131, No. 11, pp. 1147-1154. (cited 3 times)

 A delay claim often occurs when a difference between the actual completion date and the contract completion date exists. The duration of a delay is an essential piece of information required for determining the cause of a delay. However, it is difficult t o analyze a delay claim due to the fact that numerous factors that cause this delay, thereby making it a very complex issue. One of such factors is the lost productivity or loss of productivity. Despite the fact that it is one of the major causes of delay, there have been only a few studies that focus on converting lost productivity into delay duration carried out to date. Claims for productivity losses are generally t he result of  tension between the contractor and the owner. This tension arises due to the great difficulty involved in quantifying disruption effects. Thus, to calculate accurately the delay duration, a logical method for analyzing schedule delay caused by lost productivity is necessary. Therefore, in this study, we propose a m ethod for analyzing construction schedule delay where this lost productivity is taken into consideration. This methodology was implemented on a case project to ascertain its practicability, and to decide whether it can be utilized in the case of a delay claim related to lo st productivity. The significance of this paper is twofold. One is the method to convert the lost productivity into the delay duration, which can be applied to reasonable delay claim settlement. The other is the process to analyze the construction schedule delay considering lost productivity. 

Majid, M. & McCaffer, R. (1998), ―Factors of Non-Excusable Delays That Influence Contractors' Performance‖, Journal of Management in Engineering, Vol. 14, No. 3, pp. 42-49. (cited 10 times)

Delays are among the most common phenomena in the construction industry. During the last three decades delays have occurred in most types of projects, from simple building projects to the most complex projects such as nuclear power plants or tunneling works. Generally, delays may be caused by: the client (compensable delays); the contractors (non-excusable delays); or acts of God or a third party (excusable delays). This paper classifies the main causes of non-excusable delays according to the source of occurrence, then identifies the factors contributing to those causes. It is assumed that the client has more control over the compensable delays and can take action to prevent them. The contractor is expected to have control over the non-excusable delays and, presumably, do more to prevent them. Several studies have discussed the issues relating to these delays, but no major study has been conducted to examine the causes of non-excusable delays in great depth. Understanding the underlying factors that contribute to causes of non-excusable delays would help in identifying and overcoming the problems faced by contractors during the construction process. To assist in identifying the factors contributing to causes of non-excusable delays, the Ishikawa or fish bone diagram has been used as an analytical tool, and a ranking methodology has been devised. As a report of initial findings of the study, which is currently being undertaken at Loughborough University, U.K., this paper identifies materials-, equipment-, and labor-related delays as major causes of contractors' performance delays. 

Mbabazi, A., Hegazy, T., & Saccomanno, F. (2005), ―Modified But-For Method for Delay  Analysis‖, Journal of Construction Engineering and Management, Vol. 131, No. 10, pp. 11421144 (cited 6 times)

―But-for‖ is a widely used method for analyzing and apportioning project delays among the responsible parties. Despite its acceptability, the traditional but-for method suffers from serious drawbacks; namely its narrow focus on the point of view of a single party and its inability to accurately consider concurrent delays. In this technical note, several improvements have been made to the but -for method to produce repeatable results and to account for concurrent delays. Details of the modified but-for (MBF) method are provided along with an example to demonstrate its advantages. To automate the MBF method, it has been coded in a macro  program on commercial project management software. The method is simple and can help practitioners in apportioning project delays in an accurate and equitable manner. 

Nguyen, L.D. & Ibbs, W. (2008), ―FLORA: New Forensic Schedule Analysis Technique‖, Journal of Construction Engineering and Management, Vol. 134, No. 7, pp. 483-491. (cited 2 times)

While various factors such as float ownership, logic change, and resource allocation (FLORA) affect results of delay analysis, existing delay analysis techniques tend to ignore most if not all of them. To address this insufficiency this paper proposes a new schedule analysis technique called FLORA that simultaneously captures the dynamics of float, logic, and resource allocation in its analyses. FLORA analyzes not only the direct impact of a delay but also its ―secondary‖ effect. The analysis process follows ten rules that are flexible and customizable. A case study is employed to illustrate its application. FLORA yields different and more reasonable outcomes compared to the window analysis technique. Each single analysis may also yield different or even conflicting results. By properly dealing with the current issues of schedule analysis, FLORA can be more reliable. Practitioners may readily accept its analyses and outcomes because they are able to specify, modify, and consent to the rules for schedule analysis to fit into a specific context in advance. Researchers may further evaluate the impacts of different factors on delay responsibility or apply FLORA to real projects to assess its strengths, weaknesses, and potential improvements.

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Nguyen, L.D., Kneppers, J., García de Soto, B. & Ibbs, W. (2010), ―Analysis of Adverse Weather for Excusable Delays‖, Journal of Construction Engineering and  Management, Vol. 136, No. 12, pp. 1258-1267. (cited 0 times)

Severe weather conditions can be disruptive to construction. Contractors typically obtain time extensions for weather days beyond normal conditions. However, contracting parties often dispute the extent of weather-related time extensions. Typical industry contracts may overlook many important points that can provide an acceptable resolution. This paper classifies seven factors causing discrepancies in analysis of adverse weather for time extensions; namely, the definition of normal weather, weather thresholds, type of  work, lingering days, criteria for lost days, lost days equivalent due to lost productivity, and work days lost versus calendar days lost. An analysis of an actual weather-caused delay claim illustrates the impacts of those factors on t he outcomes of the analysis. A contract should define anticipated weather delay days and their lingering days and provide threshold values for weather parameters to differentiate between predictable and unpredictable severe weather. The contract should clearly def ine how a time extension is granted in calendar days as a result of work days lost, and also address how a time extension is granted due to inefficiency caused by unusually severe weather. Future research may provide an appropriate mechanism for analyzing equivalent lost days to account for lost productivity. 

Odeh, A.M. & Battaineh, H.T. (2002), ―Causes of construction delay - traditional contracts‖, International Journal of Project Management , Vol. 20, No. 1, pp. 67 –73.

Many projects experience extensive delays and thereby exceed initial time and cost estimates. In addition to imparting the economic feasibility of capital projects, extensive delays provide a fertile ground for costly disputes and claims. This paper presents the findings of  a survey aimed at identifying the most important causes of delays in construction projects with traditional type contracts from the viewpoint of construction contractors and consultants. Results of t he survey indicate that contractors and consultants agreed that owner  interference, inadequate contractor experience, financing and payments, labor productivity, slow decision making, improper planning, and subcontractors are among the top ten most important factors. It is hoped that these findings will guide efforts to improve the performance of the construction industry, and will be useful to international engineering and construction firms seeking a share in the Jordanian and the regional markets. 

Oliveros, A. & Fayek, A. (2005), ―Fuzzy Logic Approach for Activity Delay Analysis and Schedule Updating‖, Journal of Construction Engineering and Management, Vol. 131, No. 1, pp. 42-51. (cited 5 times)

This paper presents a fuzzy logic model that integrates daily site reporting of activity progress and delays, with a schedule updating and forecasting system for construction project monitoring and control. The model developed assists in the analysis of the effects of delays on a project‘s completion date and consists of several components: An as-built database integrated with project scheduling; a list of  potential causes for delays; a procedure to categorize delays; a method of estimating delay durations utilizing fuzzy logic; a procedure that updates the schedule; and, a procedure that evaluates the effects and likely consequences of delays on activity progress. This model is of relevance to researchers since it makes a contribution in project scheduling by developing a complete approach for handling the uncertainty inherent in schedule updating and activity delay analysis. It also advances the application of fuzzy logic in construction. It is of relevance to construction industry practitioners since it provides them with a useful technique for incorporating as-built data into the schedule, assessing the impact of delays on the schedule, and updating the schedule to reflect the consequences of delays and corrective actions taken. The use of fuzzy logic in the model allows linguistic and subjective assessments to be made, and thereby suits the actual practices commonly used in industry. 

Palaneeswaran, E. & Kumaraswamy, M.M. (2008), ― An integrated decision support system for  dealing with time extension entitlements‖, Automation in Construction , Vol. 17, No. 4, pp. 425 – 438.

Claims and disputes on time extension for delays are common in construction projects. Various methods and divergent approaches are used by different parties in assessing delays. Disputes then often arise on (a) eligibility of a delay event for claiming extension of time (EOT), (b) choice of method for evaluating EOT, and (c) quantification of the EOT. This research initiative aims at formulating a knowledge-based decision guidance system to help all concerned parties in navigating through these various options, in order to rationalize their approaches towards the preparation and evaluation of the EOT claims. Such rationalization is based on structured approaches, which are in turn devised from the particular contractual and project conditions. This rationalization is also expected to assist in a convergence of assessment approaches that would in turn reduce disputes and consequently wasted resources. In targeting those aims, a prototype of an integrated decision support system (DSS) for dealing with time extension claims was recently developed using (a) a structured web-based decision support framework, which is supplemented by (b) a Pocket PC based portable framework with seamless database integration. This paper presents some essential highlights on the development and usefulness of key modules of the DSS. 

Scott, S. (1997), ―Delay Claims in U.K. Contracts‖, Journal of Construction Engineering and  Management , Vol. 123, No. 3, pp. 238-244. (cited 5 times)

Contract conditions in both the United Kingdom and the United States are sufficiently similar to allow common generic delay claim scenarios to be recognized, but there are important differences in the extent of legal precedent for assessing such claims. I n the United States recognized procedures have been developed to allow critical path method (CPM) to be a dopted in this area, while in the United Kingdom the situation is much less clear. It is true that U.K. professionals will generally recognize that CPM will be useful in dealing with delay claims, but there is little evidence that a standard approach has been accepted. A survey was conducted by the writer to discover  how U.K. claims for delay were being prepared (by the contractors) and how they were being assessed (by the supervisors). Because of  the complexity of this area, the study was approached in a number of ways. This paper presents conclusions concerning attitudes towards such claims and information about the mechanisms that are being adopted to prepare and evaluate them.

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Scott, S. & Harris, R. (2004), ―United Kingdom Construction Claims: Views of Professionals ‖, Journal of Construction Engineering and Management , Vol. 130, No. 5, pp. 734-741. (cited 4 times)

 A novel approach has been used to attempt to understand how contractors justify their claims on construction contracts and how contract administrators are likely to assess them. This is done by encapsulating particular claim types into scenarios and interviewing not only contractors and contract administrators, but also claims consultants, to hear their views on how the situations represented by the scenarios should be resolved. In this paper, four areas of general uncertainty surrounding claims in the United Kingdom are described and the results of the survey on these four areas are reported. The concerns addressed are: the treatment of exceptionally adverse weather; dealing with early completion schedules; quantification of t he prolongation costs associated with an approved extension of time; and concurrent delays. The results show some good agreement, particularly on the problems of dealing with exceptionally adverse weather and with some aspects of concurrent delay assessment. Although the consensus was not so clear on the other two issues, there was a m ajority view that should give professionals working in this area greater confidence when dealing with these problems. 

Scott, S., Harris, R., & Greenwood, D. (2004), ―Assessing the New United Kingdom Protocol for  Dealing with Delay and Disruption‖, Journal of Professional Issues in Engineering Education  and Practice, Vol. 130, No. 1, pp. 50-59. (cited 2 times)

The recent publication of the U.K. Society of Construction Law‘s protocol for dealing with delay claims has finally provided a good opportunity to make progress with a continuing difficulty that besets most substantial construction projects. The protocol makes recommendations on the issues that arise when delay claims must be managed. A report of recent research is conducted to test how U.K. professionals understand some of t hese issues and how they deal with them in practice. The conclusions show some areas of  good agreement, notably in the way that early completion should be handled and the way that prolongation costs should be assessed. There are, however, areas that give rise to some concern. The methodology ―time impact analysis‖ appears not to be well used in practice, and it also seems that contractors will have difficulty with the position taken on float ownership and concurrent delays. 

Shi, J., Cheung, S. & Arditi, D. (2001) ―Construction Delay Computation Method‖, Journal of  Construction Engineering and Management , Vol. 127, No. 1, pp. 60-65. (cited 9 times)

Delay is one of t he most common problems in the construction industry. This paper presents a method for computing activity delays and assessing their contributions to project delay. The method consists of a set of equations, which can be easily coded into a computer  program that allows speedy access to project delay information and activity contributions. The proposed method contrasts the asplanned and as-built schedules. It is not based on critical path analyses; therefore, it does not require the calculation or updating of the critical path, and it is even not necessary to update the as-planned schedule, as required by the traditional delay analysis methods. The results calculated from the proposed method include various variations of activity schedules and their contributions (in days) to the overall project delay. They provide an objective baseline for determining responsibilities of delays. The method can be integrated into any delay analysis system to further improve and automate the construction delay analysis process. Practical examples are used t o illustrate the computation mechanism. 

Williams, T. (2003), ― Assessing Extension of Time delays on major projects‖, International  Journal of Project Management , Vol. 21, No. 1, pp. 19 –26.

This paper describes the standard methods currently available for assessing Extension of Time delays on major projects, and issues around such assessment. Network-based techniques have been much developed, and are powerful and credible tools for assessing the effect of a small number of discrete impacts on a project, where major reactive management actions have not been needed. The paper  points out the problems inherent in such methods in other, more complex situations, and describes the contribution that other methods using cause mapping and System Dynamics can make. These, however, are also not universally useful, and the paper describes how the two methodologies can be used together to produce useful analyses of the impact of delays on a project. 

Yang, J. & Yin, P. (2009), ―Isolated Collapsed But-For Delay Analysis Methodology‖, Journal of  Construction Engineering and Management, Vol. 135, No. 7, pp. 570-578 (cited 1 time)

Schedule delays are common in construction projects. Although many methods have been developed for analyzing and measuring schedule delays for construction projects, each method has functional limitations and use prerequisites. No one method is acceptable for all project participants under all circumstances. This study presents the isolated collapsed but -for (ICBF) method, an innovative delay analysis method for construction projects. During analysis, the ICBF method requires as-planned and as-built schedules as well as identified liability documents with key delay events to perform its analysis approach. Based on its application to an illustrative case and comparisons with other methods, the ICBF method is effective for delay analysis. Results provided by the proposed m ethod can be easily traced to the actual case in an as-built schedule.

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Yang, J. & Kao, C. (2012), ―Critical path effect based delay analysis method for construction projects‖, International Journal of Project Management , Vol. 30, No. 3, pp. 385 –397.

 Assessing schedule delay's impact on total project duration to distribute delay liability remains a controversy. None of existing delay analysis methods is perfect because including an element of assumptions, subjective assessment and theoretical projection. W indowsbased delay analysis methods are excellent in identifying and measuring construction schedule delays. Based on a previous study identifying potential problems in available windows-based delay analysis methods, this study proposes an innovative windows-based delay analysis method, called the effect-based delay analysis method (the EDAM method). The EDAM method performs delay analysis using extracted windows and determines delay impacts by considering the effects of delays on the critical path(s). According to its application to hypothetical cases and comparisons with other methods, the EDAM method is efficient in delay analysis and effective in solving concurrent delays and determining schedule shortened. The proposed EDAM method is a good alternative for schedule delay analysis for construction projects. 

Yang, J. & Tsai, M. (2011), ―Computerizing ICBF Method for Schedule Delay Analysis‖, Journal  of Construction Engineering and Management, Vol. 137, No. 8, pp. 583-591. (cited 0 times)

Schedule delay is a common construction dispute. For analyzing schedule delays, a previous study had proposed an academic analysis method, the ―isolated collapsed but-for‖ (ICBF) method. However, because many construction projects involve numerous complex activities, the procedure of using the ICBF method for schedule delay analysis is time-consuming. Therefore, this study used Microsoft Visual Basic for Applications (VBA) language and spreadsheet techniques to develop an Excel-based program for rapid delay analysis rather than manual calculation. A case study confirmed that the program automatically produces analytical results with only common delay documents (as-planned and as-built schedules and identified delay events). Compared with previous studies, schedule analysts can obtain analysis results quickly and correctly. Research results provide not only a convenient tool for schedule delay analysis but also a guide to computerize various academic delay analysis methods in the future. 

Yates, J. & Epstein, A. (2006), ― Avoiding and Minimizing Construction Delay Claim Disputes in Relational Contracting‖, Journal of Professional Issues in Engineering Education and Practice, Vol. 132, No. 2, pp. 168-179. (cited 5 times)

Delays on construction projects, and the claims which emanate from such delays, are an integral part of the modern construction process. The overwhelming amount of time, energy, and cost devoted to delay claims does not begin when a claim is initially submitted at or near the completion of a job, rather, the construction delay claim process commences at project inception. A discussion is provided relative to how claims are generated during a construction project, the various types of delay, contract provisions which may trigger  construction delay claims, methods of solidifying a party‘s position, presentation, substantiation and justification of a claim, formal and informal methods to resolve claims and, most importantly, mechanisms by which to cut down on the incidence of delay claims.