Solving the open shop scheduling problem

Only few exact solution methods are available for the open shop scheduling problem. We describe a branch-and-bound algorithm for solving this problem which performs better than other existing algorithms. The key to the efficiency of our algorithm lies in the following approach: instead of analysing and improving the search strategies for finding solutions, we focus on constraint propagation based methods for reducing the search space. Extensive computational experiments on several sets of well-known benchmark problem instances are reported. For the first time, many problem instances are solved to optimality in a short amount of computation time.