two mathematical models for railway crew scheduling problem

Railway crew scheduling problem is a substantial part of the railway transportation planning, which aims to find the optimal combination of the trip sequences (pairings), and assign them to the crew complements. in this problem, each trip must be covered by at least one pairing. the multiplecovered trips lead to impose useless transfers called “transitions”. in this study, a new mathematical model to simultaneously minimize both costs of trips and transitions is proposed. moreover, a new mathematical model is suggested to find the optimal solution of railway crew assignment problem. this model minimizes the total cost, including cost of assigning crew complements, fixed cost of employing crew complements and penalty cost for short workloads. to evaluate the proposed models, several random examples, based on the railway network of iran are investigated. the results demonstrated the capability of the proposed models to decrease total costs of the crew scheduling problem.