Types of Delay Analysis in Construction Projects

Whether it’s out of your control or not, schedule delays and disruptions are common in the construction industry. According to the 2025 Workforce Survey Analysis, 78% of construction firms reported experiencing at least one project that had been delayed.

While labor shortages are the primary cause of project delays, other events, like long material lead times, regulatory bottlenecks, and owner-initiated scope changes, are also leading contributors. Often, multiple factors coincide to halt progress.

Regardless of the cause or causes, construction delays can have severe financial impacts on stakeholders. Missing progress on a critical activity by just one day extends the project completion date and increases costs.

Analysts use forensic delay analysis to identify the root cause of delays or disruptions and substantiate their impact. This information is crucial to clarifying a dispute or claim, facilitating resolution, and ensuring the impacted parties are fairly compensated.

The Framework for Forensic Delay Analysis in Construction Claims

Forensic delay analysis is a technical investigation into how specific events impacted the critical path of a project schedule. This process doesn’t just identify that a delay occurred — it involves rigorously looking at causation and contractual entitlement and determining liability.

A comprehensive analysis typically includes:

1. Identification of the specific activities on the critical path that fell behind schedule
2. Definition of the root causes triggering the delay events
3. Quantification of the overall schedule impact
4. Allocation of responsibility for the impacts and associated project delays

Contractors may use this framework to demonstrate excusable delays and substantiate requests for extensions of time (EOT) or reimbursement for prolongation or acceleration costs. They may also use the analysis to defend against liquidated damages imposed by project owners.

Owners typically use forensic delay analysis to evaluate 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.

Industry-Approved Delay Analysis Methods

Multiple methods can be used to analyze schedule impacts. 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 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.

These fragnets are integrated into the baseline schedule and processed through Critical Path Method (CPM) scheduling software to recalculate a new completion date. The analyst can then compare the recalculated completion dates to the as-planned completion dates and quantify the delays.

The IAP method is relatively straightforward to perform. However, it assumes the baseline schedule was followed without deviation and may not address concurrent delays. It is most effective when 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 reruns the as-built schedule after removing the delays through CPM software and compares 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 logic 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 the final as-built schedule. As they compare dates between individual planned and actual activities, they can identify the causes for variances observed, such as late starts.

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

4. Time Impact Analysis

Delay analysis in construction contracts often requires time impact analysis (TIA) because it allows parties to quantify impacts in real time. While TIA is primarily a prospective modeled approach used to predict future delays, it can also be applied retrospectively to resolve disputes after project completion.

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.

When used as a retrospective analysis method, TIA involves the analyst reviewing 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 schedule immediately preceding the delay, and run it through CPM software to create a new timeline. Finally, they can compare the new completion date against the previous one to quantify the impact of the delays.

The time impact analysis requires consistent, reliable schedule updates for each impact, and can’t be used 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 the actual start and finish dates within a specific window against the planned dates 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.

Critical Nuances in Delay Analysis

Determining the appropriate delay analysis method for the situation is only part of the picture. Analysts must consider various complex factors before choosing the right method, while implementing it, and when translating their findings into a report. The following variables must be accounted for when figuring out why a delay happened and who is legally responsible for it:

Concurrent Delays

A common issue leading to construction disputes is that of concurrent delays — when two separate events, often one owner-caused and one contractor-caused, impact the critical path at the same time.

A forensic analysis must disentangle these overlapping events to determine if a delay was truly concurrent or if a party intentionally slowed their work because a separate delay had already taken place, an act known as “pacing.” Distinguishing between a concurrent event and pacing is vital for determining financial liability.

Typically, concurrent delays result in the contractor receiving an EOT and relief from liquidated damages, but no additional compensation for delay costs. Pacing results in a different outcome.

If a contractor decelerates work in response to an existing owner-initiated delay, they may be entitled to prolongation costs. In this case, the owner’s delay remains the primary cause of the project’s late completion, and the contractor’s “pacing” is viewed as a reasonable mitigation of costs rather than a secondary delay cause. 

Delays vs. Disruptions

It’s important to distinguish between delay and disruption because they result in different types of financial impacts, and therefore, how that loss must be recovered. While delay affects the project completion date, disruption impacts work efficiency and productivity.

For example, a project might still finish on time but only if a contractor accelerates work to overcome disruptions, such as by stacking trades or working out of sequence. In this scenario, the contractor’s claim is not for more time, but for the additional labor costs and lost productivity incurred to keep the project on schedule.

Forensic analysis can identify instances where out-of-sequence work or overcrowding led to productivity loss, even if the final completion date remained unchanged. Correctly identifying these instances is vital for substantiating a claim and ensuring the impacted party is fairly reimbursed for the extra costs caused by the disruption.

The Importance of Data Integrity for Delay Analysis

High-quality data is required to transform a claim from a subjective argument into an evidence-based one. That’s why it is crucial to maintain rigorous project controls throughout the project life cycle. 

To ensure a claim is defensible, the analysis requires the following:

• Daily construction reports
• Meeting minutes
• Requests for information and submittal logs
• Time-stamped photos of site conditions
• Regularly updated and logically sound schedules

Partner With 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 assists clients with construction claims, 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.

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.