Optimizing linear project scheduling with multi-skilled crews

Given the characteristics of linear construction projects, considerable research has been devoted to work productivity and continuity. However, most of these studies only consider single-skilled crews working on linear projects, neglecting the flexibility of multi-skilling in construction. Recently, researchers have revealed that multi-skilling in construction can lead to increased productivity, flexibility, and work continuity. Therefore, this study proposes a duration optimization model while introducing the concept of multi-skilling to integrate single/multiple-skilled crews to improve work performance. Moreover, to enhance the efficiency of problem solving, constraint programming (CP) is used to handle complicated combinatorial scheduling problems, and several heuristic rules involving schedules are engaged. The CP-based optimization minimizes project duration while two crew types, including single-skilled and multi-skilled crews, are integrated in the proposed model. A bridge example is used for several scenarios to illustrate the proposed modelʹs handling of linear scheduling problems, demonstrating how multi-skilling can be used to optimize project duration and improve work continuity/efficiency in a construction context.