Claims involving disruption are commonly accepted to be the most difficult to quantify. Disruptions that occur during a working day can lead to productivity loss which, in turn, can lead to time and cost overruns. If the disruption consumes the entire float in an activity, then disruption can cause a delay to project completion and lead to claims for extensions of time. Contractors of all tiers, concerned that they have lost money, troubled by the threat of liquidated damages or simply because the conditions of contract allow, submit claims for loss/expense and (in the worst case scenarios) extensions of time. The accurate quantification of the time and cost effects of such disruption is typically prevented because the role of labour/resource productivity is not fully recognised, site labour productivity is not correctly measured (if at all) and, finally, because the relationship between, in practice, the bill of quantities items (cost) and programme activities (time) is not direct
