Three stage no-idle flow-shops

The three stage no-idle flow-shop configuration, where machines work continuously without idle intervals, is an interesting manufacturing environment in many industries. Few researches have investigated this type of systems. The idle characteristic is a very strong constraint and it affects seriously the value of makespan (C max) criterion. We treat here the scheduling problem of three stage permutation flow-shop configuration with no-idle machines in order to minimise the makespan F3/no-idle/C max. An easily implementing heuristic is proposed to solve this problem with O(n log n) complexity. It finds optimal solutions for several cases. A computational study shows the result quality.