Types of Delay Analysis in Construction

Whether it’s out of your control or not, schedule delays and disruptions are common in the construction industry. For example, according to a survey of multifamily construction and development firms, 70% of respondents experienced delays in permitting and construction during the second quarter of 2024. Delays occur for many different reasons, from severe weather to poor planning.

Regardless of the reasons, construction delays can have severe financial impacts on projects. Missing progress on a critical activity by just one day can put the project off schedule and cost money.

Analysts use forensic delay analysis to identify the cause of delay and quantify its impact on a construction project. This information is crucial to clarifying a dispute or claim, facilitating resolution, and ensuring the impacted parties are fairly compensated.

What Is Forensic Delay Analysis?

Forensic delay analysis is the process of determining how a construction project schedule was impacted by one or more events that occurred during the project, as well as the causes and responsibility for those events. A delay analysis report will typically describe the following:

1. The quantification of the overall delay
2. Identification of the specific activities that resulted in the schedule delay
3. Definition of the events or causes for the impacts on those activities
4. Assessment of the responsibility for impacts and associated allocation of project delay

Contractors may use this type of analysis to demonstrate delays that were beyond their control and request a time extension or reimbursement of costs due to the prolongation or acceleration of work. They may also use an analysis to defend against liquidated damages imposed by project owners.

Owners typically use forensic delay analysis to respond to contractors’ requests or support assessment of liquidated damages for delays. In either situation, a detailed analysis is required to determine the cause of delays, communicate it clearly, and assign responsibility.  

Common Causes of Delays

Many common causes for construction delays could necessitate a forensic delay analysis. Here are a few examples:

• Unforeseen site conditions: Subsurface or other unanticipated conditions, either not disclosed or unknown at the time of bid, can cause delays.
• Contractor issues: A contractor might not adequately plan the work, provide insufficient workers, provide poor quality workmanship, have safety issues, or fall short in other ways that result in the project not progressing as planned.
• Owner impacts: An owner can impact the contractor’s performance depending on its actions or inactions. An owner may make a large number of changes throughout the project, constrain access to areas when the contractor needs it, fail to provide approvals in a timely manner or impact the contractor’s ability to perform in other ways.
• Weather impacts: A common reason for impacts is weather incidents. Excessive rain or snow, ice, extreme heat, or other conditions can lead to unsafe work conditions or impact productivity, making it difficult or impossible to complete construction work on time.
• Other reasons outside of control: The construction site might also face impacts because of situations outside the contractor’s or owner’s control. These could include manufacturers losing funding, labor strikes, labor shortages, or other similar issues. 

Industry-Approved Delay Analysis Methods

Multiple methods can be used to analyze delays. The Society of Construction Law, Association for the Advancement of Cost Engineering International, and other industry groups have described different techniques commonly used in the industry.

Selecting the right method depends on many factors, such as project complexity, the purpose of the analysis, and contractual requirements. Here are five of the most common and industry-standard delay analysis methods:

1. Impacted As-Planned

The impacted as-planned (IAP) method is an additive modeling technique. It involves inserting delay events into the original baseline, or as-planned, schedule and identifying how they affected project completion dates. If multiple activities have led to delays, the analyst can create delay fragnets. A fragnet is a group of activities leading to a delay event.

They can add the delay fragnets to the baseline schedule and run it through Critical Path Method (CPM) scheduling software to recalculate a new completion date. The analyst can then compare the modified completion dates to the as-planned completion dates and quantify the delays.

The IAP method is relatively simple and quick to perform. However, it assumes the baseline schedule was followed without changes and may not address concurrent delays. It may be most effective if delays can be clearly defined. 

2. Collapsed As-Built

The collapsed as-built or “but-for” method involves removing the delay events from the as-built schedule. The as-built schedule shows how the project actually progressed. The analyst can rerun the as-built schedule after removing the delays through CPM software and compare the completion date to the actual completion date. The difference in completion dates quantifies the associated delays.

The collapsed as-built method is generally easy to perform, understand, and present to others. However, it can be time-consuming to identify all the changes made to the baseline schedule, as well as reconstruct the as-built schedule. Additionally, this method can be prone to manipulation, and other parties may question its accuracy.

3. As-Planned vs. As-Built

The as-planned vs. as-built method is a simple, purely observational delay analysis technique. With this method, the analyst compares the as-planned schedule to an as-built schedule. As they compare dates between individual planned and actual activities, they can identify the causes for variances observed. For example, you might determine that there were late starts that led to delays.

This method can be quick and easy to perform if you already have an as-built schedule. It’s most effective to analyze short, simple projects because creating an as-built schedule for complex projects can be challenging.

4. Time Impact Analysis

Time impact analysis (TIA) is a modeled approach that can be both prospective and retrospective. As a prospective technique, it quantifies projected delays based on recent schedule updates before the impact actually occurs. The analyst can create a fragnet based on the projected delay event and insert it into the schedule to recalculate a timeline. They can compare the updated schedule’s completion date to the baseline and determine the expected impact of the delay.

TIA can also be used as a retrospective analysis method. The analyst can review the as-built schedule for delays that actually occurred during a specific period. After identifying delay events, they can create a fragnet, insert it into the existing schedule, and run it through CPM software to create a new timeline. Finally, they can compare the recalculated schedule to the baseline to quantify the impact of the delays.

The time impact analysis method is frequently cited in contractual provisions and can be more familiar to the parties involved. It requires consistent, reliable data for each impact, so you can’t use the method if this information is unavailable.

5. Windows Analysis

The windows analysis method is a retrospective technique that involves dividing the as-built schedule into shorter periods or windows. The duration of each period typically varies between one and six months. You can compare activity start and end times in each window to the baseline schedule to identify and quantify delays.

This delay analysis method has several advantages, such as a lower risk of error and manipulation. Contracts often require contractors to submit monthly schedule updates to stakeholders, so a one-month analysis window can be an ideal period to focus on. That said, the windows analysis method can be time-consuming and requires reliable periodic schedule updates.

Why Trust Spire Consulting Group

Spire Consulting Group is a construction consulting firm dedicated to the success of its client’s projects. We have over a decade of experience consulting for contractors, owners, engineers, and law firms across a vast range of industries.

Our consultants have many years of firsthand experience in CPM and delay analysis techniques and help clients quantify damages for various objectives, including validating claims and resolving disputes. You can rely on us to offer technical expertise and real-world knowledge, regardless of project complexity.

Hire Spire for Expert Delay Analysis Support

The appropriate delay analysis method is important for accurately identifying and quantifying delays, which can contribute to fair negotiations and swift dispute resolution. Still, selecting the right method can be challenging since each has pros and cons. We can help.

Spire works hard to assist clients with construction delay analyses and disputes. Our extended analyses give you detailed records of lost productivity, time, and money. We take a comprehensive approach, analyzing every detail of disruption claims. Our services extend throughout the entirety of your construction project, ensuring coverage at every point along the way.

Contact us today to learn more about how Spire performs delay analyses and supports clients throughout dispute resolution.

The content included in this article is for informational purposes only and does not reflect the opinions or recommendations expressed by any individual unless otherwise stated.