Preparing and Analyzing a Prospective Time Impact Analysis

1. Preparing & Analyzing a Prospective
Contemporaneous Time Impact
Analysis
August 9, 2007
Chris Carson, PSP
Project Controls Manager
Alpha Corporation
chris.carson@alphacorporation.com
Mark Boe, PE, PSP
Vice President
Capital Project Management, Inc.
mboe@cpmiteam.com
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publication does not necessarily reflect the views of the Construction Management Association of America or constitute a position or policy of the Construction
Management Association of America (CMAA). This material was presented with the permission of the authors and is subject to copyright under applicable law. The
information contained herein is presented as descriptive of issues related to the subject at the time it was presented, but it has not been peer reviewed or approved by
CMAA. No part of this presentation or publication is to be reproduced or used without written permission from the author and CMAA.

2. Introduction & Summary
A Time Impact Analysis (TIA) is the best
methodology for determining the extent of impact
from a potential delay event.
When done in a prospective, or forward looking,
manner, a TIA can promote negotiation and
ultimate settlement of any ramifications of a delay
event.
Performing a “Time Impact Analysis” has a
reasonably industry-wide definition.

3. Participant Expectations
Understand the terminology
Understand the difference between
contemporaneous forward-looking
prospective and backward-looking
retrospective analyses
Recognize the importance and power of a TIA
Learn how to prepare a TIA
Learn how to analyze a TIA

4. Industry Definition of Time Impact
Analysis
The Best Industry Publication
AACE International Recommended Practice No.
52R-06
TIME IMPACT ANALYSIS – AS APPLIED IN
CONSTRUCTION
Developed by a team of scheduling and dispute
resolution professionals
“Provides guidelines for the project scheduler to
assess and quantify the effects of an unplanned event
or events on current project completion”

5. Industry Definition of Time Impact
Analysis
The Best Industry Publication
AACE International Recommended
Practice No. 52R-06
“The TIA is a ‘forward looking,’ prospective
schedule analysis technique that adds a
modeled delay to an accepted contract
schedule to determine the possible impact of
that delay to project completion.”

6. Industry Definition of Time
Impact Analysis
From CPM in Construction Management,
6th edition book by James O’Brien and
Fred Plotnick, “time impact evaluation -
Use of a fragnet or subnetwork to evaluate
the impact of an event such as a change of
order or unusual occurrence on the
baseline schedule; known as TIE. This is
also known as time impact analysis (TIA).”

7. Industry Definition of Time
(Impact) Analysis
From US Department of Veteran’s Affairs:
“CPM Time Analysis on Contract
Changes: The affect that changes or
delays have on a CPM schedule is
determined by a comparison of the
schedules before and after the delaying
activities are incorporated into the CPM
Network.”

8. Time Impact Analysis Defined
Contemporaneous Prospective
Performed to “look-ahead” during project
Performed at moment of start of impact
Called Contemporaneous Time Impact
Analysis (TIA)
Compare the predicted completion of the
schedule just prior to the date of the “delay
event” to the predicted completion of the
schedule after inserting a fragnet of impact
activities into the schedule
Discussed in this webinar

9. Definition of Time Impact
Analysis
Forensic
Performed after the project or delay event
Typically used in delay analysis in claims
No industry standard name
Retrospective, backward-looking
Sometimes also called Contemporaneous TIA
since analysis is done from the beginning of
the impact even though it is analyzed after the
fact
Discussed in a future webinar

10. Reasons for Use
Sometimes mandated by specification
Best way to evaluate expected impacts
resulting from changed conditions
Supports negotiation of time extensions due
to changed conditions
Enables sharing of risk
Keeps project on track with accurate
schedule

11. TIA Specification Language

12. Case-law & Industry guidance
TIA methodology typically used and
supported in litigation
Industry publications
Construction Law Library – Construction
Scheduling, Liability & Claims, by Wickwire,
Driscoll, Hurlbut, Hillman
CMAA – CM Standards of Practice (Construction
Phase, Monitoring Schedule Compliance)
AACE Recommended Practice – noted earlier

13. Situations for Use of TIA’s
Excusable delay events
Late Notice to Proceed
Undisclosed condition
Unknown site conditions
Request for Proposal
Construction Change Directive
Field Order
Excessive predicted adverse weather conditions
Hurricane
Extended excessive hot or wet weather

14. Preparing a TIA
Verify schedule (the current schedule)
Test for reasonableness
Ensure schedule logic models the actual project
sequencing
Check for constraints
If constraints exist, establish methodology
Remove constraints, if possible
Insert logic to replace constraints
Verify accuracy of changes
Document use of methodology

15. How to Prepare a TIA, continued
Update the current schedule
Use update data through the date that will reflect the situation
immediately prior to the beginning of the changed condition
Do not make any logic changes after the update
Calculate the schedule
Set Data Date immediately prior to the beginning of the
changed condition (to match update data)
Document the completion date
Use a common activity such as Substantial Completion
(preferable), or an Interim Milestone as necessary
Use EF of the entire project
Be consistent in choosing the comparison activity

16. How to Prepare a TIA, continued
Identify the reason for preparing a TIA
Changed condition
Potential delay situation
Other actions beyond Contractor’s control
Create a copy of the reference schedule for
use in the analysis, so the reference
schedule can be used as a target
.

17. How to Prepare a TIA, continued
Determine scope of work required to deal
o
with changed condition
List assumptions
Scope of work
Manpower & resources
Sequencing rationale
Note any questionable assumptions
Provide narrative detailing how work will be
•
done
.

18. How to Prepare a TIA, continued
Create fragnet of activities
Estimate durations & document
Determine appropriate connection points;
predecessors and successors (which activities
are affected by the changed condition?)
Insert fragnet with new logic connections
AACE RP – “Set the duration of the delay
activities to zero and recalculate the CPM.”
.

19. Fragnet Example
Logic Connections
Fragnet

20. Before Rebar Shop Drawings Delay
(Original Schedule)
Act ID OD
Total Float
Early Start
Early Fin
Description

21. After Fragnet Showing Impact of Delay in Rebar
Shop Drawings
Act ID OD
Total Float
Early Start
Early Fin
Description

22. Fragnet Example
Fragnet
Logic
Connections

23. How to Prepare a TIA, continued
Recalculate project
Compare results to updated schedule
completion dates prior to insertion
Review Critical Path changes and shifts
Identify CP in schedule prior to TIA insertion
Identify CP in schedule after TIA insertion
Compare and review changes
Write up conclusions
Be prepared to discuss & defend
.

24. Typical TIA Report

25. How to Evaluate a TIA
Review schedule
Reasonableness
Logic models the project sequencing
Constraints & methodology
Verify use of correct schedule
Pre-impact schedule
Secure copy of unimpacted schedule
Updated to beginning of impact
Represents work plan before impact
The As-Planned (Baseline) Schedule should not be used
unless there is no progress (no updates) and the CP has
not changed to the beginning of the impact
.

26. How to Evaluate a TIA, continued
Review scope of work related to the changed
condition
Does it cover the changes?
Is it only new or changed scope of work?
Review assumptions & narrative
Are assumptions reasonable?
Are there inconsistencies with previous schedule?
Check for concurrent delays
TIA should take into account all delay events that
could affect completion
.

27. How to Evaluate a TIA, continued
Review fragnet
Check durations
Do they match staffing and production rates of
activities prior to impact?
Are they in keeping with durations in schedule?
Check logic within fragnet, does it make sense?
Verify fragnet calendars are consistent
Review insertion points of fragnet
Verify that predecessors & successors are “correct”
Verify that relationship types are correctly defined
Verify that any lags between fragnet and schedule are
defined and reasonable
.

28. How to Evaluate a TIA, continued
Verify that the recalculation is done correctly
Check that correct Data Date is used
Ensure that Progress Override is not changed to
Retained Logic
Verify differences between pre-impact
schedule and TIA schedule
Run comparison software
Review report to ensure that changes match
TIA narrative and logic
The schedules should be identical except for the
added fragnets
.

29. How to Evaluate a TIA, continued
Check slippage total, if any
Verify consistency in comparison of completion
•
Review Critical Path (CP)
Identify CP in schedule prior to TIA insertion
Identify CP in schedule after TIA insertion
Compare and review changes
Evaluate conclusions
Note any challenges for negotiation purposes
.

30. After the TIA
After TIA submittal & review
Negotiate time extension, if any
Document decision
If justified, incorporate TIA into schedule
Publish revised schedule with new completion
dates
Provide change order showing settlement
Ideally, TIA resolution should conclude any known
delay issues or impacts to date

31. Incorporate TIA into Schedule

32. Benefits of Use of TIA’s
Benefits to Owner
Participates in decisions that affect budget &
completion
Can negotiate requests for time and costs prior to
work
Encourages cooperation
No lingering potential claims issues
Budget & completion information always current and
reasonably accurate
Allows Owner to take advantage of pacing
opportunities
Reduce or eliminate need for unilateral modifications
Shares performance and cost risk

33. Benefits of Use of TIA’s
Benefits to Contractor
Relatively simple analyses (compared to claims)
Receives timely time extensions
Builds good documentation (even if rejected)
Allows negotiation prior to spending money or doing
work
Minimal memory problems compared to old issues
Allows for pacing other trades
Costs for TIA effort should be reimbursable
Fair preparation of TIA builds credibility
Builds in understanding of risk in pricing

34. Disadvantages of Using TIA’s
Process takes scheduling personnel with
more analytical skills and knowledge
Some added time burden (but
considerably less than building a claim)
Less attorney and consultant revenue
(only real disadvantage is to attorneys)

35. Questions?
Comments?
War Stories?

36. Preparing & Analyzing a Prospective
Contemporaneous Time Impact Analysis
August 9, 2007
Chris Carson, PSP
Project Controls Manager
Alpha Corporation
chris.carson@alphacorporation.com
Paul Beckwith, PE, CCM
Director of Construction
Regency Centers
pbeckwith@regencycenters.com