Proactive maintenance scheduling in a re-entrant flow shop using Lagrangian decomposition coordination method

Proactive maintenance scheduling is necessary to prevent facility trouble and to ensure high productivity in semiconductor production systems. For such systems, it is usually difficult to determine a proper plan because of complex process flows, which necessitate that jobs often re-enter a facility. This paper presents a method for re-entrant production floor optimization using Lagrangian decomposition coordination. By regarding maintenance as jobs that are limited by a starting and finishing time, the proposed approach produces a schedule that can facilitate proper maintenance. Feasibility is discussed using computer simulation results: the proposed method produces feasible solutions for minimizing overall tardiness problems.