BUT-FOR CONSTRUCTION DELAY
ANALYSIS – THE COLLAPSED AS-BUILT
METHOD
JANUARY 13, 2021
As discussed in previous posts on the topic, there are several methods
by which time impacts to a project can be analyzed, including windows
analysis [https://vertexeng.com/insights/using-a-windows-analysis-to-evaluate-scheduledelays/]
, time impact analysis [https://vertexeng.com/insights/the-time-impact-
analysis-method-of-quantifying-construction-delays/]
, as-planned versus as-built
[https://vertexeng.com/insights/as-planned-versus-as-built-method/]
, and impacted as-
planned [https://vertexeng.com/insights/delay-analysis-methods-examining-the-impactedas-planned-method/]
. This post focuses on one of the more commonly used
methodologies: the collapsed as-built, or but-for schedule analysis.
Here we will:
Provide an overview of the collapsed as-built method
Discuss its use in construction delay claims
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Examine the strengths and drawbacks of the method from the
perspective of construction claims analysts
FUNDAMENTALS OF THE COLLAPSED AS-BUILT
METHOD
The key principle of the collapsed as-built schedule analysis method is
the demonstration of a project’s completion without the effect of
delays caused by another party. The philosophy is that without the
other party’s delays, the project would have been completed earlier and
thus the claimant is entitled to a time extension for the difference
between that earlier date and the actual completion.
A collapsed as-built schedule analysis — also known as the but-for
analysis — starts with developing or refining the project’s as-built
schedule. Next, actual delay events caused by two parties – typically
the contractor and the owner are identified. The delays attributable to
one of the parties are removed from the as-built schedule, thereby
“collapsing” the schedule and leaving the delays caused solely by the
other party clearly visible. The resulting collapsed as-built schedule
illustrates how the project would have progressed “but-for” the delays
of the other party.
The collapsed as-built method is effectively the inverse of the impacted
as-planned method [https://vertexeng.com/insights/delay-analysis-methods-examiningthe-impacted-as-planned-method/]
. In the impacted as-planned method, the
analyst estimates project delays by taking an as-planned schedule and
adding in known delay impacts. The impacted schedule is compared
with the as- planned schedule to quantify project delays.
In the Collapsed As-Built method, the reverse is performed. The analyst
takes the as-built schedule and subtracts known delay events to create
an “unimpacted” schedule. This unimpacted schedule is compared with
the as-built schedule to quantify project delays.
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WHEN TO APPLY THE COLLAPSED AS-BUILT
METHOD
The use of the various schedule analysis methods depends on different
factors, including:
The type and complexity of the project
Time constraints
Availability of project documentation
Certain characteristics unique to the dispute will determine whether the
collapsed as-built may be appropriate for the situation.
Ultimately, but-for schedule analysis is most effective in situations
where contemporaneous updates or a baseline schedule does not exist.
Other schedule analysis models rely heavily on this data so when it is
not available the collapsed as-built approach provides a path forward.
STRENGTHS OF THE COLLAPSED AS-BUILT METHOD
The fundamental concept of the collapsed as-built schedule analysis or
but-for schedule analysis that the effect of a party’s influence can be
measured by removing that influence and comparing the results – is
easy for most audiences to grasp. As such, the approach provides a
level of comfortability that draws many to use the method. In turn, the
results of a collapsed as-built delay analysis are often easy to
understand and present. Below are some other advantages to the
model.
A STRAIGHTFORWARD WAY TO MEASURE THE IMPACT OF
CONCURRENT DELAYS
One area of delay analysis that convolutes most construction delays
claims is that of concurrent delay. Evaluating concurrent delay impacts
can be one of the more difficult aspects of any analysis. The collapsed
as-built method offers a straightforward approach to evaluating
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concurrency and is easy to convey to the opposing side. The reason is
that evaluation of concurrent delays caused by the other party is
inherent in the method itself. Identifying the actual delays of both
parties is a required step in the analysis whenever appropriate. The
collapsed as-built schedule that results from the analysis, in theory,
depicts the delay caused by the claimant’s own issues.
FEWER RESOURCES ARE NEEDED TO COMPLETE THE
ANALYSIS
Performing a collapsed as-built analysis generally requires less time and
effort when completed to other forensic delay analysis methodologies
such as a windows analysis [https://vertexeng.com/insights/using-a-windowsanalysis-to-evaluate-schedule-delays/]
. As such, use of the collapsed as-built
method may be appropriate in situations where the time to complete
the analysis, or the budget associated, is limited.
WEAKNESSES OF THE COLLAPSED AS-BUILT
METHOD
A major drawback to the as-built schedule analysis model is that the
absence of contemporaneous schedule data can make it more
susceptible to manipulation. This is because such information is critical
to the reliable development of the as-built schedule that forms the very
basis of the analysis.
Because aspects of the as-built schedule that forms the basis of the
analysis often relies on subjectivity, an analyst can frame the analysis as
needed to illustrate their argument. The root issue is the data used to
develop the as-built schedule. It is inevitable that the opposing side will
challenge the as-built start and finish dates for activities, making
contemporaneous documentation critical to establishing the utilized
dates.
Furthermore, based on the identified actual dates, as-built schedule
logic is applied between the activities. The determination of the
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appropriate logic can be highly subjective and have a drastic influence
on the findings of the analysis. Establishing the validity of the as-built
schedule data is paramount to any delay analysis that relies on the
collapsed as-built method. This can be a difficult task if
contemporaneous project record information is not available or limited.
SUMMARY OF THE COLLAPSED AS-BUILT METHOD
The collapsed as-built method is recognized as an adequate method to
determine delay allocation. But-for analysis of delays provides a simple
and easy to understand solution to quantifying project impacts. This
analysis is usually done — and works best — with projects that have
good as-built schedule information but lack contemporaneous schedule
information, such as monthly updates, or there is no reliable baseline
schedule available. The lack of contemporaneous information, however,
also lends itself to criticism of the as-built schedule developed by the
claimant. Therefore, it is important to maintain strict guidelines and
thoroughly consider all available project documentation.
If you have questions about this brief discussion on the Collapsed AsBuilt Method or other delay analysis models, or to learn more about
VERTEX’s Construction Claims Consulting
[https://vertexeng.com/services/construction/construction-claims/]
services, call
646.553.3500 or submit an inquiry [https://vertexeng.com/contact-us/] .
THE AUTHOR
ANDREW SARGENT
PSP
Managing Consultant
Primarily focused on contract disputes, Andrew provides strategic risk
management and dispute resolution services to sureties, owners, developers,
institutions, and design professionals.
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