Time Impact Analysis Method

Table of Contents

What Is Time Impact Analysis?

A Time Impact Analysis (TIA) is a time-estimating technique that demonstrates the cause and effect of a change to a CPM (critical path method) time schedule. The aim of a Time Impact Analysis is to identify a discrete issue and determine its relationship to activities or past delays in order to substantiate the impact a delay may have on a project time schedule.

Time Impact Analysis (TIA) is an approach to analyze delays on a project. You have to develop a fragnet, which is a fragmentary network for the issue (i.e. the change). It’s like a mini-schedule for the change. You take that fragmentary network, you drop it into a contemporaneous schedule, and then look to see how it affects that schedule. That’s the Time Impact Analysis.

A Time Impact Analysis is a method used to determine the extent of impact from potential delays in the construction works. This Time impact analysis involves adding new activities indicating changes or delays into an updated schedule representing progress up to the point when a delay event occurred to determine the impact of those delayed activities

A time impact analysis is a method used to determine the extent of the impact that change order or delay will have on the overall project schedule. This is a “forward-looking” analysis since it focuses on the impact of events that have already occurred or are presently occurring.

TIA will be most effective for projects using the CPM (critical path method) for scheduling. The time impact analysis (TIA) focuses on a specific event, by providing a snapshot of the impact event & integrating it into the project’s current critical path.

When to use the Time Impact Analysis Method?

The Time Impact Analysis method can be used in both prospective (forward-looking) and retrospective (retrospective or forensic) delay analyses.

For prospective delay analysis, TIA is often the preferred method. Indeed, the United States government revised its standard scheduling specification in 2015 to require the use of the Time Impact Analysis method for prospective (forward-looking) analyses.

The Time Impact Analysis method works best in forward-looking (prospective) delay analyses because the viability of a TIA diminishes as more time passes between the identification of a delay/change and the preparation/approval of the TIA. When a significant time has elapsed, an owner may believe that unrelated contractor-caused delays have diluted the effects of the owner’s delays.

As the impact of the prospective TIA is absorbed into the project record/actual data, the value of the findings of the prospective TIA diminishes to the point where a more thorough forensic analysis is more appropriate. For these reasons, it is critical that prospective TIAs are prepared and reviewed immediately following the identification of a change or delay.

Types of Delays

There are two main types of delay:

Excusable Delays
Non-Excusable Delays

Excusable delays occur when the affected party is allowed to claim for an extension of time, compensation, or both. Meanwhile, non-excusable delays are delays that the main contractor/subcontractor or the affected party needs to bear responsibility.

General steps for performing a Time Impact Analysis

Analyze the Contract
Reviewing and validating /compiling an as-planned schedule
Insert fragnet of activities representing delays into a reasonable as-planned schedule
A constructability review of the impacted schedule
Identify variances between planned & impacted schedules
Causation analysis
Identification, quantification & apportionment

How to Perform TIA in Construction (Time Impact Analysis)

Properly performing a TIA (time impact analysis) requires attention to detail and sometimes can be time-consuming, but it will produce the most precise results. Read below an overview of how a true time impact analysis works.

1-Identify the Impact Events

Impact events can be change orders, delays, or any other event that may impact the overall project finish date. The first step is to collect the documentation & identify what additional activities are required to correct the impact. This should show the sequence of activities & time it will take to finish the additional work required.

This is often called creating a “fragnet” (short for “fragmented network”). Consider a fragnet a miniature CPM schedule for whatever is impacting the project time schedule. By identifying how the change will be undertaken, it’s easy to determine how much time the change will take, and how that change will affect the overall time schedule.

2-Identify the Current Project Time Schedule

Project time schedules are changing all the time. Select the most current time schedule available. The TIA will fail if using an outdated version of the time schedule.

3-Add the New Activities to the Time Schedule and Analyze the Impact

The next step is to plug the fragnet into the project time schedule. Again, “fragnet” simply refers to the mini-critical path which represents what work is required due to the event that’s changing the project time schedule. Basically, it’s just a mini-programme for the new work.

This requires identifying any logical relationship sequence between activities. If one task will depend on some other task first being completed, that should be noted. Once the fragnet is correctly inserted into the time schedule, be sure that the activities still follow a logical path. If there are any scheduling issues, make any necessary adjustments, and document the changes.

4-Recalculate the Critical Path

Finally, you can analyze what sort of impact the event had on the overall project schedule. Determine whether the event had any impact on the critical path or any interim milestones. Compare the original time schedule to the impacted time schedule to determine if and how long the contract finish date has been affected.