Document Type

Conference Proceeding

Publication Date


Publication Title

16th IFAC World Congress, Prague


Manufacturing systems, factory automation, supervisory control, logic controllers, optimization


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 orders or inaccurate estimates of processing times. This paper presents an approach for job-shop scheduling with uncertain arrival times. The approach exploits Virtual Supervisor (VS) concept, which provides access to all system information during program execution and thus can readily monitor the overall system performance. The goal is to minimize expected part tardiness and earliness cost. A solution methodology based on a combined Lagrangian relaxation, VS-Patterns, Maxwell equations and temporal difference is developed to obtain a dual solution for on-line implementation.