A note: Minimizing maximum earliness on a proportionate flowshop

Most classical scheduling objective functions have been studied in the context of a proportionate flowshop. In most cases, the solution was shown to be identical to that of the single machine version. In this note we introduce a rare case where the extension to a proportionate flowshop leads to a different solution. Specifically, we study the problem of minimizing maximum earliness. We show that the problem remains polynomially solvable, but the running time of our proposed greedy-type algorithm is larger than that of the single machine case.