The two-machine ow-shop serial-batching scheduling problem with limited batch size

We consider the the two-machine ow-shop serial-batching scheduling problem where the batches have limited size. Two criteria are considered here. The rst criterion is to minimize the number of batches. This criterion re ects situations where processing of any batch induces a xed cost, which leads to a total cost proportional to the number of batches. The second criterion is the makespan. We study the complexity of the problem and propose polynomial-time algorithms for some particular cases and an approximation algorithm with a guaranteed performance for the general case.