Scheduling a multi-stage fabrication shop for efficient subsequent assembly operations

Consideration is given to scheduling the operation of a multi-stage fabrication shop producing the component parts of a major commercial refrigerators producer. The objective of this scheduling problem is the determination of both production sequences and lot quantities at each stage so as to meet production targets and ensure continuous operation of subsequent assembly stations. After describing the problem within its natural context, we present an algorithm for the dynamic scheduling of the fabrication shop. This applies general planning principles adapted to the needs of the environment under consideration and makes use of existing heuristic rules for arriving at sequencing decisions. Although in no sense optimal, the algorithm can provide good feasible solutions to a previously not formally analysed problem. After being incorporated into a systematic computer-aided scheduling procedure, the algorithm has been actually implemented, demonstrating considerable improvements over previous fabrication shop scheduling practice.