The document outlines the process of performing Time Impact Analysis (TIA) to assess delays in construction projects, differentiating between excusable and non-excusable delays. It emphasizes the need for a forensic planner to identify fragnets, select suitable updated programs, and analyze the impact of delays on project completion dynamically. The TIA method is recommended for use during the occurrence of delays to determine entitlement for extensions of time for completion effectively.

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How to perform Time Impact Analysis (TIA)
Amr M. Morsy, Consolidated Contractors Company, April 2017
The planned project completion date usually cannot be achieved in construction projects, due to
unexpected delays that were not planned for before the project commencement. Those delays
can be considered excusable delays if they were attributable to the Employer, while they can be
considered non excusable delays if they were attributable to the Contractor. To avoid the
application of Liquidated Damages on the Contractor, the Contractor shall prove his entitlement
to Extension of Time for Completion through confirming that the dominant delays are excusable
delays. There are many delay analysis methods that can be used to analyze the project delays
and quantify the entitlement for the Extension of Time for Completion.
Time Impact Analysis (TIA) method in one of the most reliable methods to analyze and quantify
the entitlement for the Extension of Time for Completion during the project, as stated by AACE,
it is recommended that the TIA method to be used “forward looking” or “ prospective analysis”
approach.
The benefit of using the TIA method is that it is a dynamic method, which shows the status of
the project in the period of occurrence of the delay. So, the concurrent delays can be viewed to
calculate the correct entitlement for EOT for the Contractor, if those concurrent delays were
attributable to the Contractor and overlapped with the Employer’s delays, those delays period
shall be deducted from the Contractor’s entitlement as shown in figure 1.

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Figure 1

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To start performing the TIA on delay event, the forensic planner (delay analyst) needs to identify
the fragnets to be incorporated in the schedule, and that can be achieved through acquiring all
the correspondences, RFIs, VORs, etc.… related to that delay event.
It is essential to have an approved or consented programme to insert the fragnets in. the next
step in performing the TIA is selecting the suitable updated programme for progress. This step is
one of the most important steps in the TIA, as it depends on the type of delay whether it is due
to additional works, change in the type of materials, installation method, suspension of works by
the employer, etc.….
To select the suitable updated programme for progress, the delay analyst needs to identify the
delay start date, and then select the last updated programme for progress prior to the delay
start. In case there was an activity in the P6 Programme for receiving instructions to start works
in specific location, receiving the IFC drawings, or receiving materials delivered by the Employer,
the delay start date will be the late start date for that activity. In case of receiving an instruction
to change the type of material, check the late dates for the activities related to that material
(Engineering, Procurement, and Installation), then check the date of instruction. If the date of
instruction is earlier than the dates of those activities, then there is no need to perform the TIA,
as there will be no time impact from that delay event. While, if the date of instruction is later
than the late dates of those activities, then the delay analyst needs to select the last updated
programme for progress prior to the late start of those activities.
After selecting the suitable updated programme for progress, use two copies of that updated
programme, rename one of them “before impact”, and the other one “after impact”. Insert the
prepared fragnets in the “after impact” programme, and link them to the related impacted
activities. Create new activity code and rename it with the delay event and assign that code to
the fragnets and the impacted activities. Run the programme, then check the new longest path,
assign that activity code to the activities on the new longest path and then assign the “before
impact” as a baseline to the “after impact” programme. Compare between the two programmes
on the impacted path to see the extent of the delay on the impacted activities, using the filter of
the “used activity code”.
After performing those analyses, now the delay analyst has the expected impact from that
delay, also the delay analyst needs to transfer the “used activity code” and check the longest
path in the “before impact” programme, to view the actual delay till the data date of that
programme, and to check if the impacted activities filtered by “used activity code” are on that

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longest path to justify that delay. In case those impacted activities are not on the longest path,
the delay analyst shall try to relate the delay in the “before impact” programme to another
delay event caused by the Employer, to avoid the deduction of that delay period resulted from
the “after impact” programme. If he could not find justification to the delay or relating it to the
Employer delays, then the overlapped period between the two delay paths will be deducted
from that delay period resulted from the “after impact” programme.
TIA method proved that it is a reliable method to use to identify the impact of the delays on the
project completion, but it is recommended to be used during the occurrence of a delay event
and it’s impact, not after the end of that delay event and it’s impact.