Delay impact analysis method for lost productivity in construction projects

Schedule delays commonly appear in construction projects and result in delay claim progressively. Several studies have proposed various schedule delay analysis methodologies. By using the as-planned and as-built schedules, most previous studies focus on the impact calculation of identified delay events on project duration. They consider the schedule variances between the as-planned and as-built schedules, but ignore to connect delay evidence to as-built schedule. Lost productivity, one essential delay cause, is usually experienced by a contractor while accomplishing its works less than planned rate of production. In a construction project, a contractor usually suffers certain damages by lost productivity caused by the owner or the third party, but the schedule impacts from the damages are not easily evaluated. How to calculate the schedule impacts by lost productivity plays a key role for solving a delay claim with lost productivity. This study tries to propose a delay analysis method for considering the schedule impact of lost productivity. With a simplified case study, the proposed method can be used as a tool to calculate the schedule impacts of schedule delays with lost productivity.