TIMED PETRI NETS FOR TEXTILE BATCH PLANNING UNDER VARYING INPUT CHARACTERISTICS

摘要

Batch planning and scheduling of textile dyeing and finishing operations, is a complex problem, particularly under non homogenous input and highly varying operating requirements. Here the focus is on the conceptual planning stage during which valid approximation-based methods are needed. This paper introduces a decomposition method, directly derived from Timed Petri Nets (TPN) theories, to calculate the expected utilization of the processing equipment and to derive simple operational decision rules leading to maximum system productivity at steady state, for given characteristics of the textile input mix and its required routing through the manufacturing system. The decomposed TPN model enables a quick calculation of the resource expected utilization at steady state thus providing a stick yard against which to verify its long run simulation based utilization estimate.