Synopsis: Changes to the execution of the project impact time... and as the adage
goes time is money.
1. Introduction: Time Impact Analysis (TIA)
To support a value engineering proposal, variance request/ change order, claim or
request for equitable adjustment a formal, analytical quantitative (as opposed to
qualitative) Time Impact Analysis method needs to be prepared by the party stating
a time impact to the schedule (usually this would be the Contractor).
The analysis must be self-standing and self-evident by which we mean that any reader
(not necessarily familiar with the finer details of the project) should be able to
easily read, understand and in principle agree to the statements and conclusions
of the time analysis. Further all supporting documentation such as memos, emails,
letters, technical clarifications, incident reports, daily progress reports, weekly
progress reports, etc. as pertinent should be included as an appendix and/ or highlighted
in the main body of the time impact analysis.
2. Process: When to submit a Time Impact Analysis
The Contractor will need to submit a Time Impact Analysis (TIA) illustrating the
influence of each change or delay on the Contract Completion Date or milestones.
Unless the Client requests an interim update to the schedule, the current updated
progressed schedule as accepted by the Client will normally be used to display the
impacts of the change.
Each TIA needs to include a Fragmentary Network (fragnet) demonstrating how the Contractor
proposes to incorporate the impact into the project schedule. A fragnet is defined
as the sequence of new activities and/ or activity revisions, logic relationships
and resource changes that are proposed to be added to the existing schedule to demonstrate
the influence of impacts to the schedule. The fragnet needs to identify the predecessors
to the new activities and demonstrate the impacts to successor activities. The Contractor
will run the schedule calculations and submit the impacted schedule with the proposal,
claim, etc. and include a narrative report describing the effects of new activities
and relationships to interim and contract completion dates, with each TIA. The official
time extension requests will then include the Time Impact Analysis showing the fragnet,
impacted schedule (with fragnet loaded), Total Float Report, Narrative Report, Log
Report and any other relevant documentation.
If the TIA is accepted by the Client, then all changes in the fragnet used to determine
impacts, will need to be incorporated into the schedule.
Note: It is important for the Contractor or incumbent party to prepare the Time Impact
Analysis as soon as possible, preferably the moment the event impacting the schedule
is potentially identified or takes place.
3. Analysis: Present Progressed Schedule vs. Subsequent Progressed Schedule
The TIA including the fragnet analysis must take place using the present progressed
schedule. It is incorrect to attempt to analyze a past event (especially if this
has taken place some substantial amount of time back) with a "subsequent" schedule
(meaning a progressed schedule much beyond the date of the event that impacted the
schedule e.g. using the final progressed schedule to analyze an event that took place
half way through the project).
Below 3 fragnets illustrate the point. The first is the original fragnet based on
the approved baseline schedule. Let's assume that later the "free-issued" equipment
was supposed to have been delivered and available at the construction site on the
start of the 20th day. However subsequently on day 01 the Client notifies a delay
in the delivery of 5 days. Hence the Contractor on day 01 could then claim 5 days
schedule impact. However if the Contractor was to put the claim at the end of the
Construction period, and let's assume that the Contractor suffered delays while pouring
concrete extending the duration from 5 days to 8 days, then he could claim only 2
days vs. 5 days in the earlier case.
Of course in the latter case for example the Contractor could claim that the delay
was intentional due to the activity for concrete pouring having additional float.
However reality is considerably more complex than this basic example, and often there
exist a myriad of variables and interdependencies. The point is as illustrated in
this example is that the TIA should be performed as soon as possible and using the
progressed schedule at the time that the event having an impact on the schedule is
4. Keep your copies of the Progressed Schedules - As Native Files!
Important note! In my experience - unfortunately - I have found many Contractors
that do not keep native copies of their progressed schedules, instead rely on pdf
copies, and continue to recycle the same native file for all their progressed schedules.
The end result is a baseline schedule and the schedule at the project completion
- without any intermediary schedules in a native format. This is a very poor practice
and makes subsequent "forensic" schedule analysis very difficult.
To substantiate a time claim it's imperative to have extremely clear records including
copies of all progressed schedules as native files. Otherwise your chances to have
the claim accepted are compromised.