Skip to content


Assessment of Disruption Claims

Typical Issues

When Contractors or Subcontractors experience disruptive events, which impact productivity in the delivery of the works, an examination of the following typical issues arises:

  • Establishing causation based on contemporaneous facts and records kept by the Contractor.
  • Post facto analysis by reference to statistical data, earned value and productivity ratios.
  • Finding a measured mile where unimpacted productivity can be contrasted with impacted performance elsewhere.

In our experience, disruption claims are notoriously difficult to prove unless the claim is compiled intelligently.

The Society of Construction Law define “disruption” as:

“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 activities. Because of the disruption, these work activities are not able to be carried out as efficiently as reasonably planned (or as possible).”

Assembling a successful disruption claim requires the development of a factual matrix of events and causes that give rise to disruption. Ideally, this will be compiled relative to causative events such as RFIs, lack of coordination, cumulative impact of numerous variations, limited site access, crowding /trade stacking, late delivery of free issue materials, out of sequence works, and inadequate supervision.

The impacts of disruption need to be set out across a monthly timeline, detailing the events that give rise to unrecovered hours, impact labour productivity and cause any consequential losses, such as equipment productivity and associated logistics support. For example, equipment, plant, and machinery can be impacted by disruption: prolonged non-critical activities and/or disrupted site presence as tasks are extended will give rise to increased costs.

Evaluation can be undertaken in a variety of methods, depending upon the record keeping and data available. Effective evaluation relies upon accurate and up-to-date record-keeping such as daily reports and, ideally, timesheets, recording the impact at a work face or sections of the work. Global claims should be avoided, comparing the original tender with actual expended hours of production.

Where possible, a measured mile should establish a ratio of expended hours and the quantities of production achieved in months where the Contractor has been subject to no or a small degree of disruption. This can be used as a yardstick of the Contractor’s peak productivity during this time period. Ratios of the quantity of a similar type of work will be essential to indicate where months have resulted in significant unrecovered hours and production losses relative to that type of work being undertaken each month.