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Delay Analysis - Windows Analysis Method vs. Time Impact Analysis (TIA) or Time Impact Evaluation (TIE)

6 replies [Last post]
Kristopher Coronel
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Hi Guys/Gals,

I have a confusion about the difference between Window Analysis Method and Time Impact Analysis and also about Time Impact Anaysis and Time Impact Evaluation when use in Delay Analysis.

Please maybe some body out there can explain this jargons.



Khuong Do
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I write an article regarding How to perform Time Impact Analysis / Window Analysis in Primavera P6.

If you're interested, kindly read it here

Patrick Weaver
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For a basic summry of the various options see:

The main paper is Assessing Delay and Disruption - Tribunals Beware 

AACEi have a very detaild practice note on this topic.

Elsayed Ibrahim
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there is no any difference just only primary method and derivative method

please see the following table

Time analysis methods as per the following table

General Approach

Primary Method

Secondary Derivative Methods


1.Impacted As-Planned



·      Chronological Addition of Delays (one at a time)

·      Gross addition (all delays at once)

2.Time Impact Analysis

·       Chronological Events analysis

·      Windows analysis

·      Contemporaneous  impact analysis


Collapsed As-Built

·     Chronological insertion of delays (one at a time)

·     Gross Insertion (all delays at once)

·     Windows analysis (delays in each windows)


As-Planned vs As-built

·    Total time assessment

·    As planned vs As-Built windows analysis

·    Contemporaneous windows analysis

·    Month to month update

Mike Testro
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Hi Barry

I am not quite sure what you are asking.

Completed work to the left of the data date has no float because it has finished.

Uncompleted work to the right may have its float affected by early or late completion of work to the left.

Since a typical delay analysis focuses on zero float tasks it is only when the available float is remove by late completion of predecessors that they form part of a delay analysis.

Best regards

Mike Testro

Barry Fullarton
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Hi Mike


Have been reading with interest on GPM and Forensic Total Float , interesting on what it says and has a good basis on CPM to the left and right of the data dates


What is your perspective on this ?

Mike Testro
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Hi Kristopher

Time Impact analysis (UK Definition) is a one off retrospective delay analysis excercise.

Windows Analysis is the same thing repeated many times in different time slots - even if you know what happened in the following months you have to pretend that you don't know. That makes it useless for forensic work.

For work in progress the Impacted as Planned method (UK Definition) goes on as the work progresses - that makes it a Windows analysis.

Best regards

Mike Testro