A Comparative Study of Different Integer Linear Programming Approaches for Resource-Constrained Project Scheduling Problems

Over the last few decades, the resource-constrained project scheduling problem (RCPSP) has been considered a challenging research topic in operations research and computer science. In this paper, we have primarily proposed two different integer linear programming (ILP) models for RCPSPs. As the computational effort required for solving such models depends on the number of variables and constraints, our proposed mathematical models were carried out while attempting to reduce the required number of variables and constraints. For better demonstration, four other ILP models for RCPSPs were also considered so that they could be compared with our proposed models. That comparative study was conducted by solving standard benchmark instances while using a common objective function. The study provides interesting insights about the problem characteristics, model sizes, solution quality and computational efforts required for solving those ILP models.