These problems relate to real-time planning for orders, and reaction and adjustment to any kind of disturbance (e.g. accidents,
weather changes, or equipment breakdowns). Most of these system elements vary with time and show a non-deterministic behavior. Current decisions depend on both the present information and an estimation of the future, and the objective is not only to minimize the costs, but also to maximize reliability of the system. Table3 and Fig. 5 reviews the relating little work that has been carried out on operational planning problems. In order to discuss the different problems, models