Delay Analysis

Why Delay Analysis is Important in Construction.

Last Updated on July 12, 2022 by Admin

For both the employer and the contractor, time is of typical importance when completing a job. Due to this, contracting parties now have a strong incentive to evaluate project delays in order to make informed judgments regarding prospective time and/or expense compensation claims.

Virtually every construction project experiences delays, and as a result, each project has a different set of contributing factors. Delay is sometimes described as a time overrun or an extension of time needed to finish the project on schedule. Once the reasons for the foundation have been recognized, delays will be eliminated.

Delay in construction could be described as the passage of time past the deadline set forth in a contract or past the day set out by the parties for project delivery. For the owner, a delay means losing money because there aren’t enough manufacturing facilities and rental space, or they have to rely on their current facilities. Delays can often result in increased overhead expenses for the contractor due to lengthier work periods, higher material costs due to inflation, and higher labor costs.

The cause of delays on a construction project is determined via delay analysis, along with the effects such delays are predicted to have on the overall schedule.

One party to the contract may file a lawsuit as a result of the analysis findings. Applying numerous delay analysis methodologies, all of which are based on construction programs initially created for managing the project, is a popular strategy frequently used by contractors and their employers (or their representatives) to tackle this issue.

What is Delay in construction?

Construction project delays are a significant problem notwithstanding the successes they have achieved. Delay is the difference in time between the projected completion date and the actual completion date as specified in the contract.

Construction delays are defined as a time difference between the start and finish of an activity relative to the baseline timetable, or as a late start or late completion of an activity, directly affecting the stipulated cost.

Construction delays are frequently caused by poorly managed events and can be viewed as a risk for the project if it is identified, analyzed, and managed in a systematic process at the beginning. If this risk is managed, minimized, shared, mitigated, or accepted, it can produce positive results and reduce the likelihood of further delays. In terms of the development of antagonistic relationships, mistrust, litigation, arbitration, and cash-flow issues, delays in construction projects have a detrimental impact on clients, contractors, and consultants.

What are the types of delays in construction?

One of the most prevalent problems in building projects that lead to disputes and claims is a delay. Delays result in a total loss for all parties involved, who lose in one way or another. The following sorts of delays are the most common: Excusable and non-excusable, Critical and non-critical, Concurrent, and Compensable or non-compensable.

Excusable and non-excusable delays:

Excusable delays occur when the contractor is entitled to a deadline extension, payment, or both under the terms and conditions of the contract. Excusable delays are those brought on by unforeseeable circumstances outside of the construction parties’ control. Excusable delays can be further divided into two categories:

Excusable non-compensable delays are those that are brought on by a range of circumstances outside the control of the owner, contractor, or the other party. Contractors are permitted to extend the construction timeline during this type of delay. Such delays represent a divine intervention.

Excusable compensable delay: The owner or his agents are to blame for these delays. The owner gives the contractor a reasonable amount of time and money to do the project.

Nonexcusable delays:

Non-excusable delays are those when the contractor is solely to blame for the activities that were delayed and led to an increase in project length. These are the result of negligence and fault on the part of the contractor or subcontractor. According to the terms of the contract, the contractor may be required to pay the owner compensation.

Critical and non-critical delays:

A crucial delay is one that causes the project’s length to increase. These delays depend on the project’s critical path. A delay in the critical path activities might affect how quickly a project is finished. There may be more than one critical path in some projects, which leads to disagreements concerning delays that have already happened. A non-critical delay is one that does not lengthen the project’s duration. Non-critical delays do not affect the project’s completion time, but it is important to keep in mind that delays that are on the critical route may do so if they exhaust the available float.

Concurrent delays:

A concurrent delay is when many delays take place at the same time, impacting various tasks simultaneously or separately and delaying their completion. Concurrent delays are those that are brought on simultaneously by various parties and may affect the project’s completion date. This type of delay is the most challenging because both parties can use it against the other.

Contractors will use this delay to waive their excused delays, while the owner will use it to collect liquidated damages. In the event of justifiable delays, the contractor is entitled to a time extension in case the completion date is postponed. Additionally, such delays may have an impact on non-essential tasks, which should be taken into account with a more thorough analysis or float time adjustment.

Compensable or non-compensable Delays in Construction Projects

When delays are compensable, the contractor is responsible for Time Extension & Cost Compensation. Excusable delays encompass all compensable delays, but non-compensable delays refer to delays that are only the contractor’s fault. However, depending on the circumstances it has caused and the terms of the contract, non-compensable may fall under critical, non-critical, excusable, or non-excusable categories.

Causes of delay in construction

Understanding how project delays develop is crucial for the project manager to have while overseeing projects. Only then would they be able to stop them from happening or handle them when they unintentionally do. The following are a few of the most typical reasons for delays:

Inefficient management

With today’s knowledge of construction, we can manage projects effectively to ensure that the necessary quality is delivered in the needed amount of time. The aforementioned requirements cannot be met without this management. In contrast, if your construction management procedure wasn’t efficient, a worse outcome can be just around the corner.

In one of the projects, the entire project was being built, but despite following a construction plan, there were significant delays.

In response, the management team began investigating the causes. Surprisingly, a very basic factor seemed to be the primary reason for the delay. It was the tendering process; bad management caused the project costing to be completed in a hurried manner, which resulted in numerous errors. Many of the BOQ Items’ budgeted costs were incorrectly computed, which led to an erroneous Cash Flow.

These errors not only resulted in a cash flow issue and prevented the contractor from completing the planned objective, but they also significantly delayed the project’s completion date and pushed its status to the point where recovery plans are virtually unattainable.

In the end, a construction project management plan covers much more than simply the price phase, and failure could occur in any of the other project stages unless they are all correctly carried out and each has a precise implementation time.

Construction implementation failure

It is crucial for any contractor to submit these method statements before the project begins to ensure they are approved and that they will allow the engineers to execute the construction works properly to meet the required quality and specifications. Executing a construction project requires full knowledge of the method statements made for each construction item/element.

Even the most straightforward building projects might have several unforeseen failures if this issue is not taken carefully. As a result, one of the frequent reasons for construction project delays is the contractor’s failure to carry out some tasks adequately, which necessitates starting over after learning what went wrong with the initial execution.To determine the precise construction method that can be used, each item must be carefully analyzed.

Environmental catastrophes/Unavoidable events

Due to the yearly change in seasons, every building project that lasts more than a year will unavoidably be exposed to various environmental occurrences. For instance, there are some really rainy days in the winter that make it impossible for employees to carry out any construction operations (especially concrete).

The only thing the safety precautions can accomplish in these situations is to safeguard the lives of the workers. However, safety prevents them from overcoming these obstacles and moving on to the implementation phase. Until further notice, when the weather is favorable for working, all work must be placed on hold.

Rain is just one example of an environmental catastrophe; there are many others. Storms, hurricanes, earthquakes, high-temperature conditions, and more are a few instances of potential Force Majeure events. Accordingly, if these conditions had an impact on the project’s essential tasks, there would undoubtedly be a delay.

Design issues

Each construction project may be broken down into three stages, which stand for all the tasks needed to complete the project from the first day to the very last. These phases are, in brief order:

  • Design
  • Execution
  • Post-construction maintenance and operation

Here, we’ll focus primarily on the initial step (Design). The project’s deadline may be seriously threatened by this stage because the execution phase is when difficulties are typically identified. No matter how carefully the design is altered or examined, the execution stage reveals any flaws in the design. You might actually learn about it in a very unpleasant way, like when you build a concrete part and watch it crumble or deform just a few days later.

When a design flaw is uncovered, it can cause a project to be delayed for months due to its variety and sheer number.Now we can see how critical the engineering work (Shop-drawing) that is necessary both before and throughout the execution phase. Not only does it assist the execution team in carrying out the project correctly, but it also aids in the early discovery of design flaws, giving us time to address the issue before the corrupted piece executes.

Scope increase

As we all know, any project’s main parties are:

  • The owner (client)
  • The engineer (consultant)
  • The contractor

Of course, there can be more parties but these are the most important of them.

The owners, however, typically begin the initiatives without fully understanding what or how they want it to be in the future. For instance, the owner decides the project will include 4 buildings, of which 3 have been designed but the 4th has not yet been decided upon or created. In this situation, the owner informs the contractor that there will be an increase in their scope, which by default means an increase in the project length, and they begin the project while deciding what to do with the remaining portions of the project that the contractor is unaware of.

This increment may take the shape of an entirely new B.O.Q. or minor addition to the B.O.Q. Ultimately, it is recommended that every owner be completely informed of the project scope before it is allocated to a contractor in order to minimize any needless lengthening of the project’s timeline.

Economical Changes

The project cash flow becomes monotonous and no longer accurately reflects the true valued/budgeted cost per time as a result of the unexpected change in the price of everything. Unless both the contractor and the owner can find/afford a financial solution to the calamity, this immediately drops a tremendous influence on the project’s timeframe, making it double or triple the original duration (perhaps putting the project on hold or even exterminating it).

The owner must agree to a change in the project’s duration and give the contractor an extension of time if such a solution is not feasible.

Failure in coordination between time schedule and execution

One of the frequent errors made by contracting organizations is underestimating the value of a project’s time schedule. The project can be completed successfully and within the needed time period with the help of a good time schedule.

Additionally, it aids in getting the project back on track if it ever veers off from its initial course. Additionally, it warns the project team of any impending problems and offers ways to get around them.
Not to mention the benefit of the delay analysis in developing a revised plan that helps the project team to recover from present delays and prevent further delays, should a delay arise.

The project manager’s main tool and greatest companion is a time schedule. Imagine implementing a project without a timetable; the outcome is certain to be a failure since significant delays would inevitably materialize.

What is delay analysis in a construction project?

The cause of delays on a construction project is determined via delay analysis, along with the effects such delays are predicted to have on the overall schedule. One party to the contract may file a lawsuit as a result of the analysis findings.

The goal of delay analysis is to determine how much of the project delay can be attributed to each party (contractor, owner, or neither) by computing the delay and working backward from there. This will allow time and/or monetary compensation to be decided.

Schedule delay analysis is typically a difficult process that depends on the circumstances. When there are numerous sources of delay with connected consequences, analysis of the delay is more challenging.

The most popular and complete instrument for schedule delay analysis is the project schedule. The schedule is changed frequently, so all pertinent information can be entered to display it later.
With the use of the computerized scheduling tools currently on the market, the project scheduler is able to monitor:

  • Dates of the real start and end.
  • The time period after an activity’s initiation during which it is suspended.
  • As the project moves forward, a log is kept. It is possible to enter all previous data for usage in the future.
  • They can be hidden from view in the printing and used only for internal reference.
  • Activities that each party involved is individually responsible for might be categorized as delay activities.
  • Later, they can be removed for analysis.
  • To compare the progress visually, target bars and current/actual bars can be displayed side by side. For the target dates and the current/actual dates, a table can be created similarly.
  • Leaving the original schedule aside, it is possible to make copies and conduct analyses for alternative scenarios resulting from the delay or change orders. Even for complicated networks and complex projects, the analysis can be seen rapidly.
  • Images can be added to layouts to more effectively display certain activities and achievements.

Delay Analysis Methodologies

To quantify delays that happened during a project, a variety of forensic schedule analysis techniques can be applied. The following are the most popular delay analysis techniques:


In order to estimate their potential effects, delay events are introduced into a baseline or as-planned schedule as part of the impacted as-planned analysis. In order to express delayed events using logic, the baseline or as-planned schedule must be modified to reflect additional activities. The delay is measured by the time interval between the project’s completion date in the affected as-planned schedule and the original as-planned schedule. This approach is straightforward and does not need an as-built timetable. However, because it doesn’t rely on as-built data, it is regarded as a hypothetical model.


An impacted as-planned analysis is basically the reverse of a collapsed as-built analysis. Using this strategy, you can figure out when the project would have been finished ‘but for’ the delay events by eliminating them from the as-built timeline. This approach is simple to comprehend and does not call for contemporaneous schedule changes or an as-planned timetable. With the addition of post-facto logic linkages and delayed events, it can be manipulated.


A straightforward technique for comparing the baseline or as-planned schedule to the as-built schedule or a schedule update reflecting progress is the as-planned vs. as-built analysis. With this strategy, activities on the critical and near-critical routes are compared to their actual start and end dates rather than the planned start and finish dates. This shows when things take longer to start, go on longer, and end. Simple projects with short durations and a single, distinct critical path that doesn’t change during the project are best suited for this approach. As the actual critical path diverges from the anticipated timeline, its accuracy declines.


The time impact analysis (TIA) is a thorough method for calculating the impact of each delay event by independently analyzing them in chronological sequence. Using the schedule that existed before and after the delay occurrence, this methodology assigns a numerical value to each delay. The length of the delay is determined by the difference between the project’s completion dates before and after the incident. TIA is often simple and quick to complete and does not require an as-built timeline. When utilized to quickly address delayed performance during the project, this strategy is well-accepted. As it does not use as-built data, it is regarded as a hypothetical model, and if there are many delay events, it may be difficult to execute.


The windows analysis is a retrospective technique that estimates the as-built critical route delays for each of the smaller time periods (often referred to as “windows”) that make up the entire project duration. This method of analysis compares the anticipated critical path of the baseline or as-planned schedule to the actual schedule, which takes into account the actual conditions for each chosen period. This approach often relies on the schedules in the condition they were submitted at the time (“as-is”). It is simple to calculate and comprehend the windows analysis. It takes into account current conditions and actual construction progress and identifies delays as well as acceleration quantities. The windows analysis, however, is time-consuming, necessitates full project records, and is dependent on accurate baseline data, such as as-planned schedule and performance data.

Final Thought

Cost overruns are a common problem that arises whenever construction delays occur. A strong management structure must serve as the foundation for any building project. Maintaining effective coordination between all parties involved in the project and the execution teams is also essential. A combination of skilled experience, careful planning, and utilizing innovation typically results in that sweet spot of least delay and most efficiency.

To effectively estimate delays, it’s crucial to choose the right delay analysis technique. To choose the approach that is best for the given instance, analysts must be aware of the benefits and drawbacks of each strategy. When choosing a technique for delay analysis, it is important to take into account a number of aspects, such as contractual obligations, the accessibility of source data, the available money, the time allotted for the study, and the scale of the dispute.

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