Line Balancing Strategy for Re-Entrant Manufacturing

Scheduling in a re-entrant manufacturing environment is a complex task that requires a scheduler to handle a larger number of uncertainties than in a traditional manufacturing environment. Many input control strategies and dispatching rules are applied to re-entrant processes to achieve fast and relatively effective solutions. However, due to the complexity of these processes, the dispatching rules currently employed in general flow shops do not guarantee the consistency of results despite the benefits of these rules. To address this issue, an extremely robust drum-buffer-rope-based releasing and holding scheduling method is proposed in this paper. An overview of the proposed method is presented, including the process by which the re-entrant process is reconfigured into independent flow shops and the balancing of the production loads among individual loops. Nine scheduling scenarios comprising different combinations of three loop load measurement parameters and three loop-balancing methods are employed to test the applicability and performance of the proposed method.