Cyclic scheduling in flow lines: Modeling observations, effective heuristics and a cycle time minimization procedure

In this paper the authors address the cyclic scheduling problem in flow lines. They develop a modeling framework and an integer programming formulation of the problem. The authors subsequently present exact and approximate solution procedures. The exact solution procedure is a branch-and-bound algorithm which uses Lagrangian and station-based relaxations of the integer programming formulation of the problem as the lower bounding method. Our heuristic procedures show a performance superior to the available ones in the literature. Finally we address the stability issue in cyclic scheduling, demonstrate its relationship to the work-in-progress inventory control of a fiow line, and present a very simple procedure to generate stable schedules in flow lines.