A fast branch & bound method for the open-shop problem based on a disjunctive graph formulation of the problem is developed. Computational results show that the method yields excellent results. Some benchmark problems from the literature were solved to optimality for the first time.
Brucker, P., Hurink, J. L., Jurisch, B., & Wöstmann, B. (1997). A Branch and Bound Method for the Open Shop Problem. Discrete applied mathematics, 76(1-3), 43-59. https://doi.org/10.1016/S0166-218X(96)00116-3