A Constraint Programming Model for Balancing and Scheduling of Flexible Mixed Model Assembly Lines with Parallel Stations

In this paper, we study flexible mixed model assembly lines with serially connected stages where stages may have one or more parallel stations. Station parallelism in flexible mixed model assembly lines improves system reliability and enables rapid adaptability to customer demand fluctuations. In this paper we consider task assignment, model and task scheduling problems simultaneously. Due to its success in solving combinatorial problems, we develop a Constraint Programming model for the problem and test its performance using various size instances. The results reveal that, the model outperforms a Mixed Integer Programming model and a decomposition scheme given in the literature.