Isolated Collapsed But-For Delay Analysis Methodology

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 method can be easily traced to the actual case in an as-built schedule.     

Delay Analysis Method Using Delay Section

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 and 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 method of contemporaneous period analysis. The writers’ points are illustrated through the use of an example case.     

Schedule Analysis under the Effect of Resource Allocation

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 may 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.     

Modified But-For Method for Delay Analysis

“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.     

Delay Analysis within Construction Contracting Organizations

Delayed completion of a construction project is often caused by a complex interaction of a combination of events, some of which are the contractor’s risks and others are the project owner’s. The apportionment of the liability to give effect to the risk allocation has therefore been a matter of great controversy. Many delay analysis methodologies have been developed over the years for performing this task. This paper reports on an empirical study into the current practice in the use of these methodologies in the United Kingdom, as part of a wider study aimed at developing a framework for improving delay claims analysis. The part of the study reported here was based on a questionnaire survey of key informants. The issues investigated include the categories of staff within contracting organizations who contribute to delay claims analyses, the awareness, use and reliability of existing delay analysis methods and the obstacles to their use in practice. The main findings of the study are that: (1) the preparation of delay claims often requires input from commercial managers (quantity surveyors), schedulers, site managers, external claim consultants and estimators; (2) commercial managers have the greatest involvement; (3) claims analyzed using the as-built versus as-planned and the impacted as-planned techniques are often successful although there is considerable literature on the shortcomings of these techniques; and (4) the main obstacles to the use of the methods relates to deficiencies in project records and scheduling practice.     

Method for Calculating Schedule Delay Considering Lost Productivity

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 to 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 the 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 method 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 lost 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.     

Delay Analysis under Multiple Baseline Updates

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 the 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 to 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.     

Daily Windows Delay Analysis

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 modified 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.     

Avoiding and Mitigating Delay and Disruption Claims Conflict: Role of Precontract Negotiation

Delay and disruption claims often generate conflict and contract dispute in the delivery of building and civil engineering projects. If construction delay claims conflict can be avoided or mitigated, there could be substantial financial savings on projects. This study explores the effect of precontract negotiation as a means of avoiding or mitigating delay and disruption claims conflict. The data collection instrument was a structured questionnaire administered face to face on 41 contractors’ personnel on 41 completed projects in Singapore. The data were analyzed using structural modeling with partial least squares estimation approach. The results indicate that when the contractors received an unfavorable outcome from the contract administrator’s decision on their claims for delay, the intensity of conflict was lower when there was precontract negotiation and precontract agreement regarding the rules for quantifying and assessing the impact of anticipated delays than when there was none. It was also discovered that the higher the level of precontract negotiation and precontract agreement on the rules for quantifying and assessing delays, the higher the contractors perceived the quality of the decision-making process for delay claims during the construction phase. Further, the higher the contractors perceived the quality of the decision-making process for delay claims, the lower the intensity of conflict. At the time of entering into contracts, owners and their project management team need to pay more attention to precontract negotiation and agreement with their contractor to clarify and agree on the rules for quantifying and assessing the impact of anticipated delay and disruption. Aspects that require precontract negotiation, agreement, and clarification include: the rules of evidence for claims, the record requirements for claims and the procedure for keeping the records, form of construction program including the software for the preparation of the program and the procedure updating the program, the methodology for analyzing delay claims, formula for quantifying unabsorbed head office overhead component of prolongation cost, the method for quantifying disruption cost, the handling of concurrent delays, profit—whether claimable and the rate of profit to be paid, acceleration—circumstances under which it will be compensated and basis of compensation, and the question of who owns the float. These are, typically, not adequately covered by most standard forms of contracts. The agreements on these matters may be incorporated as part of partnering agreement or as a supplement to the contract agreement. Precontract negotiation, clarity, and agreements could produce instrumental and noninstrumental (social psychological) effects, which could facilitate delay and disruption claims assessment and their resolution. It could mitigate conflict even when the outcomes are unfavorable to a party.     

No-Damages-for-Delay Clause: Evaluating Contract Delay Risk

In recent years, there have been a number of construction disputes involving no-damages-for-delay clauses in construction contracts. This paper reviews the legal aspects of the no-damages-for-delay clause and presents in an easy-to-use flowchart the issues that need to be addressed to resolve disputes involving the no-damages-for-delay clause. Analysis shows that the clause presents a formidable obstacle for contractors to overcome if monetary damages are to be recovered. The contractor in most instances needs to show that the owner or the owner’s agent caused active hindrance or the owner demonstrated bad faith toward the contractor. The language of the clause is critical to determining the risk it conveys to the contractor. Examples of minimal, intermediate, and maximum risk language are given.     

FLORA: New Forensic Schedule Analysis Technique

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.     

Assessing the New United Kingdom Protocol for Dealing with Delay and Disruption

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 these 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.     

Using Weibull Analysis for Evaluation of Cost and Schedule Performance

Large amounts of money are lost each year in the construction industry because of poor schedule and cost control. Few contractors specify and follow systematic schedule monitoring practices. Traditionally, the earned value method (EVM) is used to control and monitor schedule performance using the schedule and cost performance indices which compare the budgeted cost of work performed to what was originally scheduled or what is actually expended. This paper presents a statistical approach, namely Weibull analysis, to evaluate stochastically the schedule performance of construction or design projects. The approach can be used in conjunction with the EVM to enhance the evaluation and control of schedule performance. Weibull analysis is a common method for failure analysis and reliability engineering used in a wide range of applications. In this paper, the applicability of Weibull analysis for evaluating and comparing the reliability of the schedule performance of multiple projects is presented. The various steps in the analysis are discussed along with an example in which two projects are analyzed and compared. The authors conclude that Weibull analysis has several advantages and provides a relatively robust and effective method for construction managers to better control and monitor their projects.     

Delay Time Analysis in Microtunneling Projects

Delay in microtunneling projects is a complex multivariate problem. Delay in microtunneling is defined as the nonworking time of a microtunneling project due to any reason other than scheduled stops. There are many reasons for delay such as mechanical failure of system components, leakage of hydraulic hoses, blockage of slurry pipes, and waiting time for excavated materials hauling equipment. Delay time increases the project duration and consequently the project cost. Delay data were collected from 35 microtunneling projects. Collected delay data were delay duration, delay reason, time, and location from the start to the stopping point. Five categories of delay causes were used in the analysis. Prediction of delay time will enhance the estimation accuracy of microtunneling project duration. A predictive model using a probabilistic approach was selected to represent the delay time. Based on data characteristics, a Weibull distribution was determined to best represent the overall delay duration in microtunneling projects. Using “regression with life data,” expected overall delay in a microtunneling project could be predicted as a function of driven length. The model will help contractors to estimate total project time with reasonable accuracy. Knowing the anticipated delay time will allow contractors to have a point of comparison for actual performance.     

Delay Mitigation in the Malaysian Construction Industry

This paper describes the importance of applying proper management in dealing with delays in construction for a growing economy. The main objective of this paper is to identify the management tools that are practiced in the local construction industry in mitigating delay. It also aims to identify the main factors that lead to project delays and to suggest recommendations on how to overcome or mitigate effects of the problem. Data is gathered from responses from questionnaire survey and interviews with those involved in construction project. The surveys and research findings indicate that delay incidents occur mainly during the construction phase of a project and one or more parties usually contribute to delay. This paper highlights the importance of having more experienced and capable construction managers as well as skilled laborers to enable the industry to develop at a faster rate either nationally or internationally.     

Multiple Simulation Analysis for Probabilistic Cost and Schedule Integration

One of the major goals of the construction industry today is the quantification and minimization of the risk associated with construction engineering performance. When specifically considering the planning of construction projects, one way to control risk is through the development of reliable project cost estimates and schedules. Two techniques available for achieving this goal are range estimating and probabilistic scheduling. This paper looks at the integration of these techniques as a means of further controlling the risk inherent in the undertaking of construction projects. Least-squares linear regression is first considered as a means of relating the data obtained from the application of these techniques. However, because of various limitations, the application of linear regression was not considered the most appropriate means of relating the results of range estimating and probabilistic scheduling. Integration of these techniques was, therefore, achieved through the development of a new procedure called the multiple simulation analysis technique. This new procedure combines the results of range estimating and probabilistic scheduling in order to quantify the relationship existing between them. Having the ability to accurately quantify this relationship enables the selection of high percentile level values for the project cost estimate and schedule simultaneously.     

Delay Reporting Within Cost Accounting System

There is an imbalance in the visibility of costs of delays in the daily construction site work routine and the costs of overhead expenditures which to a large extent determine the magnitude of these delays. This imbalance frequently means that overhead expenditures are carefully scrutinized while delay costs may be totally ignored. The resulting suboptimization may not result in the lowest total project cost. A procedure is proposed to address this problem. The procedure works within existing cost accounting systems and is a modification of existing foreman-delay survey methods.     

Flexible Work Breakdown Structure for Integrated Cost and Schedule Control

Integration of cost and schedule control systems has been an issue of great concern for researchers and practitioners in the construction industry. Nevertheless, the real-world implementation of this promising concept has not been popular enough to maximize the benefits that this integration has to offer. One of the major barriers is the overhead effort to collect and maintain detailed data. The purpose of this paper is to propose a flexible work breakdown structure (WBS) that optimizes the overhead effort by means of reducing the amount of data to be controlled. In order to have a flexible structure, the WBS numbering system needs to utilize standard classification codes and should not have a common strict hierarchy for all components. A case study is analyzed in this paper in order to examine the proposed concept. Practical implications are outlined as well.     

Contractual Approach for Facilitating the Resolution of Dispute over a Contractor’s Failure to Comply with Time Limit for Notice of Delays

The enforcement of a contractor’s notice of delays and claims as “a condition precedent” to a contractor’s claims is a controversial issue among practitioners, researchers, and legal scholars. Strict enforcement or liberal interpretations (no enforcement) of time limit for a contractor’s notice have some implications for the success of projects and for the construction industry. This paper examines and compares the different views regarding enforceability of notice provisions. The paper evaluates those views and thereafter proposes an alternative contractual approach for dealing with a contractor’s noncompliance with the provision. The applicability of the proposed approach is evaluated vis-à-vis legal principles. The proposed approach appears to be practical and equitable. It could facilitate early resolution of disputes relating to notice. It could also make the outcome of notice-related dispute more predictable. Considering the contractual, legal, and practical problems that could arise from a strict enforcement and a liberal interpretation (no enforcement) of time limit for a contractor’s notice, the paper highlights the benefits of the proposed approach to the employers (project owners), contractors, and the construction industry at large.