Expert Witness Journal Issue 65 February 2026 - Flipbook - Page 29
Widespread Disruption Causing
Delay… Or Is It?
by David Waddle, DipICArb FCIOB FAPM MCIArb AMICE
poor quality drawings and speci昀椀cations and change
order ine昀케ciencies.
Introduction
Many of us in the world of construction are aware of
the term ‘disruption’ but what does it actually mean?
In the UK, the SCL Protocol1 describes disruption
as “a disturbance, hinderance or interruption to a
Contractor’s normal working methods, resulting in
lower e昀케ciency.”
To be able to consider and quantify the e昀昀ects of
disruption it is necessary to 昀椀rst determine that
disruption has in fact taken place or that the project
is currently being disrupted.
Spotting disruption is easy, right?
And in the United States, the AACEI Recommended
Practice note provides a list of some common types of
disruption that can be experienced on engineering
and construction projects2. These include:
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Well maybe not so easy. The clue to disruption
lies in those last four words of the SCL’s de昀椀nition:
“resulting in lower e昀케ciency” – that is to say, lower
productivity.
Absenteeism
Acceleration
Adverse weather
Availability of skilled labour
Changes and rework
Competition for trade labour
Labour turnover
Crowding / stacking of trades
Defective work
Dilution of supervision
Excessive overtime
Failure to coordinate trade contractors
Fatigue
Labour relations
Learning curve
Materials and equipment shortages
Overmanning
Poor morale
Out of sequence working
Site or work area restrictions
Site conditions
Untimely approvals or responses
When carrying out its regular progress update,
a contractor might 昀椀nd that it is on programme –
there is no delay, and no disruption – so all is good
with the world. Well, that may not be strictly correct.
Consider this. What if the contractor had planned to
install 100m of pipework per week and the progress
update showed that it had in fact installed 100m of
pipework per week. Traditionally that would be the
end of the story. However, what if the planned work
was to be carried out using a single two-person team
but instead, two teams actually completed the work
– a total of four people not two?
In this situation, the planned production was
achieved but productivity was not.
This is by no means an exhaustive list and I am sure
that you will be able to come up with several more.
What is often not appreciated across the industry
is the subtle di昀昀erence between production and
productivity. Production is a measurement of output
whereas productivity measures the labour hours
required to achieve a unit of output.
Is there disruption to the works?
How do we value disruption?
In 2023, a survey in the United States found that 45%
of contractors experienced a decline in productivity3.
The survey found that some of the top causes of
productivity issues included poor planning and
communication, poor site logistics management,
There are several ways of assessing disruption. The
SCL Protocol provides a summary table of the more
common methods of measuring disruption4.
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It describes the productivity-based methods as being
the preferred methods and they are listed in order
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FEBRUARY 2026
