Optimal Scheduling of the Reentrant Multi-Degree Cyclic Multi-Hoist Scheduing Problem

摘要

The current paper deals with the cyclic multi-hoist scheduling problem in electroplating lines considering rentrance. Identical parts are produced with processing time windows. Moreover, re-entrance is also considered. These together make it more challenged to obtain better schedules improving the productivity. To achieve this, multi-degree cycles are considered. To our best knowledge, this is the first research in this generally complicated scenario. In order to maximize the productivity of the production line, i.e. minimize the cycle time for a given degree, operations of hoists are first analyzed in detail to avoid their collision. Then, operations related the re-entrance are modeled. Based on these work, a mixed integer linear programming model is proposed. An industrial instances is used to test the proposed model. It is solved using the commercial software ILOG CPLEX. Results illustrate the efficiency of the proposed approach.