The final core principle of the SCL Delay and Disruption Protocol — Core Principle 22 — addresses the question of which period should be used to evaluate compensation for prolongation and disruption. The answer, like that for prolongation cost generally, is principled and rooted in causation.
For prolongation cost, the correct period for evaluation is the period during which the compensable delay event was actually causing additional time-related cost — typically the period when the event was extending activities on the critical path. This is not the same as the period of overall project overrun, which may occur much later (or even before, in cases of sequential delay) and may reflect a different cost structure.
For disruption cost, the correct period for evaluation is the period during which the disruption event was affecting productivity. This is identified through the disruption analysis itself — typically by reference to the measured mile comparison between disrupted and undisrupted periods of the same activity, or by reference to the contemporaneous productivity records during the disrupted period.
The practical importance of this principle is significant. A contractor that calculates prolongation cost by reference to the cost rate at the end of the project, when most resources have demobilised, may significantly under-claim. A contractor that calculates prolongation cost by reference to peak deployment cost when in fact the delay occurred during a low-activity period may significantly over-claim and undermine the credibility of the entire claim.
In Middle Eastern arbitrations, this principle is frequently the source of substantial differences between the parties' experts. The contractor's quantum expert may seek to apply a high resource cost to the entire period of overrun, while the employer's expert may seek to apply a low cost to a narrow window. A robust delay analysis identifies the specific periods of compensable delay; the quantum analysis then applies the actual cost rate during those specific periods.
Together, the 22 Core Principles of the SCL Delay and Disruption Protocol provide a comprehensive framework for the analysis of delay and disruption claims. They are not law in any jurisdiction, but they are widely respected by tribunals across the Middle East and internationally, and they form the analytical backbone of the work of every reputable delay and disruption expert witness operating in the region.