In this article, we will attempt to discuss delay due to disruption effects on construction projects and to explain the usage of the measured mile method used to quantify delays due to disruption.

First, we reference SCL Protocol 2017 on the objective of performing Disruption Analysis, under Core Principles No. 18 (page 43) of the SCL Protocol 2017 and I quote below:

“Compensation may be recovered for disruption only to the extent that the contract permits or there is an available cause of action at law. The objective of a disruption analysis is to demonstrate the loss of productivity and hence additional loss and expense over and above that which would have been incurred were it not for the disruption for which the Employer is responsible.”

Secondly, we reference SCL Protocol 2017 on the relation between Disruption and Delays to a project, under Core Principles 18.1 of the SCL Protocol 2017, and I quote below:

“Disruption (as distinct from delay) is a disturbance, hindrance, or interruption to a Contractor’s normal working methods, resulting in lower efficiency. Disruption claims relate to loss of productivity in the execution of particular work activities. Because of the disruption, these work activities are not able to be carried out as efficiently as reasonably planned (or as possible). The loss and expense resulting from that loss of productivity may be compensable where it was caused by disruption events for which the other party is contractually responsible.”

Thirdly, we reference SCL Protocol 2017 on examples of disruption that affects the works, under Core Principles 18.1 of the SCL Protocol 2017, and I quote below:

“Disruption events can have a direct effect on the works by reducing productivity (such as piecemeal site access different from that planned, out of sequence works or design changes). They can also lead to secondary consequences on the execution of the works, for example through crowding of labour or stacking of trades, dilution of supervision through fragmented work gangs, excessive overtime (which can lead to fatigue), repeated learning cycles and poor morale of labour which can further reduce productivity.”

Our Short Answer:

“The measured mile approach is one that a contractor can prove its lost productivity on a construction project. The measured mile approach compares the cost of impacted work with the cost incurred to perform the same or similar unimpacted work. Measured mile calculation is based on comparing impacted productivity and unimpacted productivity on the same project. By this measure, it is generally a more acceptable approach.”

Figure 1: Showing A Sample Bar Chart of Baseline1, AsBuilt2 and Disrupted Analysis As-Built3

The first step is to determine the type of disruption that occurred for a certain activity or group of activities. This is easier said than done but it is absolutely crucial to perform this task accurately and
in an objective manner. Further, we must identify that the cause of the disruption itself are not caused by the Contractor which is self-explanatory.

The second step is as equally as important as the first step. We must identify when the disruption occurred and also the location of where the disruption occurred.

From Figure 1 above, we must determine for Productivity for Period A (Unimpacted Productivity) and Productivity for Period B (Impacted Productivity).

It is important to note that Productivity for Period A are normally differs from the Productivity for Baseline or Productivity for Tender. Productivity for Period A are the actual Achieved Productivity
or Realistic Productivity.

Further, we need to stress the importance that the Productivity for Period A is for the same activity at the same location as determined for Productivity for Period B. And it is clearly crucial that the determined Productivity for Period B be less than Productivity for Period A.

Once we have obtained the Productivity for Period A and Productivity for Period B, we can determine the difference between the two and from this, we can determine the additional time required due to the disruption. Simply said, due to disruption additional time is required to perform Portion B of the activity.

The following simple formula explains relation between Productivity and Time:

[Productivity = Output / Time], Assume Output = Constant
[Time = Output / Productivity], Assume Output = Constant

Good record keeping is important and crucial toward the accurate calculation of claimed productivity loss and support. Contemporaneous record keeping from the beginning of the project right through the end of the project is required to determine the period of no disruption to the period of disruption.

Learning curve take up rate for period of No Impact or Minimal Impact to be considered as this could artificially prolong the period of No Impact or Minimal Impact.

Baseline period or Period of No Impact or Minimal Impact to be sufficiently or reasonably long to obtain accurate or reasonably accurate Productivity for a period of no disruption or minimal disruption.

Important to consider that the impacted activity due to disruption was not impacted by another matter or matters that can be proven to be caused by the Contractor themselves.

Society of Construction Law Delay and Disruption Protocol 2nd Edition February 2017 (“SCL Protocol 2017”)