On-line Scheduling Method of Manufacturing System Based on Virtual supervisory Algorithm for Reference Pattern

In this paper, a scheduling method is developed provide planning for manufacturing plants with multiple coordinating cells. The controls for reconfigurable manufacturing systems have to be capable not only of identifying exceptions on-line, but also simultaneously developing on-line strategies for unpredictable customer order changes or inaccurate estimate of processing times. The approach exploits virtual supervisor (VS) concept developing an algorithm which provides access to all system information during program execution and thus can readily monitor the overall system performance creating reference pattern. The goal is to minimize expected costs of part tardiness and/or earliness. A solution methodology based on a combined Lagrangian relaxation, VS-Patterns, Maxwell equations and temporal difference is developed to reduce the computational requirements for large problems. Sequences pattern shows that near optimal schedules can be obtained a dual solution for on-line implementation.