Methods of Forensic Schedule Delay Analysis

Methods of Forensic Schedule Delay Analysis
Methods of Forensic Schedule Delay Analysis

Construction projects have their own typical problems resulting in construction disputes. Time is one of the most important component of a construction product. If it is not used efficiently, delays and time overruns will occur. These delays may have cost impacts on the project and both the contractor, subcontractors and the client may be effected. Therefore, Forensic Schedule Delay Analysis methods are used for resolving disputes between the parties participated in the construction projects.

Delay situations are are getting complex based on the nature and the complexity of the construction projects. During construction, multiple delays can occur concurrently and can be caused by more than one party. Delay analysis and claim management is an unavoidable process in a construction project which requires effective tools and techniques to resolve the disputes.

Forensic Schedule Delay Analysis Methods

Delay analysis is a process of answering the below questions
– How late is the project ?
– What has caused the project to delay ?
– Who is responsible for the delay ?
– What is the cost impact of the delay ?

Project duration and delays can be calculated by the help of the Critical Path Method. Forensic schedule delay analysis is the investigation of tasks and the activities by using CPM scheduling methods to model the real project situation to resolve delay claims through negotiations or legal processes.

Although there are several approaches for performing construction schedule delay analysis, there is no standard method. Association for the Advancement of Cost Engineering AACE recommended nine “method implementation protocols” for delay analysis. Other related associations and professionals recommended several methods for this purpose.

There are four commonly used methods for Forensic Schedule Delay Analysis

– As-Planned vs As-Built Analysis
– Windows Analysis
– Time Impact Analysis
– Collapsed As-Built

As-Planned vs As-Built Analysis

As-Planned vs As-Built Analysis is widely used for the comparison of the planned and the actual performance of the work. The dates and durations of the activities are selected from the baseline schedule and compared with the actual schedule. The main benefit of this method is that it is easy to perform and understand.

Below are some limitations of As-Planned vs As-Built Analysis

– Concurrent delays can not be measured
– The logic and the sequence changes as the work performed but this method ignores this fact.
– It is not easy to implement this method to the complex projects.

Windows Analysis

In the Windows Analysis the overall schedule is divided into windows with a selected duration. Then the activities within the selected window is updated by the expert considering the delays. Responsibility for each delay is determined by analyzing the windows. Windows Analysis method provides accurate information for the delays when there are regularly updated CPM workschedules. It is difficult to manipulate.

Below are some limitations of Windows Analysis

– Workschedule may not be updated regularly with correct dates.
– Baseline schedule may not prepared accurately
– Activities outside the selected window may have impacts on the activities inside the window.

Time Impact Analysis

Time Impact Analysis is a delay analysis method that considers the cause and effect of a change to a critical path method (CPM) schedule. An event that causes delay is identified and its relationships with the activities are determined by using this method. Time Impact Analysis is a useful technique for analyzing complex schedules and determining concurrent delays. However it has some limitations.

Below are the limitations of Time Impact Analysis

– Can be expensive and time consuming
– Can be susceptible to manipulation

Collapsed As-Built

In this method, the expert uses the actual as-built schedule and takes out the duration of all the delays attributable to the contractor. As-built critical path is determined by analyzing the activities of this revised schedule. Collapsed As-Built analysis is a useful technique for determining concurrent delays.

Below are the limitations of Collapsed As-Built

– Preparing a revised schedule is time consuming and expensive.
– Manipulations can be made while making the revised schedule.
– The expert must make substantial decisions.


Forensic Schedule Delay Analysis Methods are closely related with right CPM calculations. In order to make substantial CPM calculations, the baseline schedule should be prepared properly. As mentioned in the article there is no standard method for making Forensic Schedule Delay Analysis. Deciding which method of making delay analysis is based on the type and the characteristics of the delay.


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