This paper considers a flowshop scheduling problem with a waiting time constraint imposed to restrict the processing of the two operations of each job. If the second operation of a job cannot start within a specified waiting time after the completion of its first operation, then an extra processing time will be incurred for its second operation as a penalty. We first show that is even a greatly...

This paper analyzes different representations for permutation flowshop problems. This is done using forma analysis to assess the quality of these representations with respect to makespan optimization. Classical recombination operators are studied and empirically evaluated in this context. It is shown that the best operators work on representations in which absolute positions of tasks are releva...

In this paper a generalized version of the tardiness flowshop permutation scheduling problems is considered. A mathematical programming formulation, in the form of a combinatorial optimization model, is also developed. Then a genetic algorithm is developed for solving the proposed problem. The efficiency of the developed algorithm is evaluated through a computational experiment, in which severa...

We consider in this paper a two-machine flowshop scheduling problem in which the first machine processes jobs individually while the second machine processes jobs in batches. The forming of each batch on the second machine incurs a constant setup time. The objective is to minimize the makespan. This problem was previously shown to be NP-hard in the ordinary sense. In this paper, we first presen...