Resolution of some 2-stage hybrid flowshop scheduling problems

In this paper we propose a synthesis of works dealing with a particular two-stage hybrid flow shop. We know its significance for modeling many real manufacturing workshops. There are M((1)) identical machines at the first stage and only one at the second. The optimized criterion is the maximum tardiness. In a first time, machines are always available. Two heuristic resolution methods are given and compared. In a second time one of these methods is particularized when the number of available machines is not lower than M((1)) - 1 at each time. It allows to take a maintenance policy into account. In both cases Linear Programming formulations are given : whereas this approach is not very effective, problems are so accurately explained.