Calculating the cost impact in loss of productivity claims

Loss of productivity is a major type of claim for construction projects. Maintaining exact records and calculating the impact of productivity losses in a timely manner are difficult for general contractors in formulating such claims. This study introduces an add-on tool that automatically calculates the cost impact of productivity loss using Primavera P6. By inputting the actual quantities and resource data, the tool calculates the impact by comparing the actual quantities and workhours before and after the claimable event occurs, based on the measured-mile approach. The total cost of indemnity is derived by considering the indirect cost incurred by the project delay as well as the direct cost caused by productivity loss. The applicability of the tool was validated through a case study and interviews with industry experts. This tool helps practitioners to reliably organize data from the field in real time, which will eventually help them manage claims effectively.