بارگذاری پالت بر روی ماشین های مشابه CNC با برنامه حلقوی

Flexible manufacturing systems (FMS) are generally set up to process a wide variety of parts with low to medium volume demand. The loading problem in FMS is a short-term decision issue, which addresses the simultaneous processing of a set of different parts in an efficient manner on capital-intensive resources. This study focuses on cyclic schedules in loading pallets carrying groups of identical parts to CNC machining centers. A predefined stream of pallets fixtured for different part types is repeatedly supplied to every CNC machine in cycles. Moreover, a limited number of pallets have to be shared among the cycles of machines to keep utilization and the overall throughput rate at acceptably high levels. The solution approach is an integrated mix of optimization and simulation methodologies. The validation of the model is based on data from past 6 months of operation. Comparisons are made retrospectively.

Flexible manufacturing systems (FMS) is a manufacturing environment which consists of a group of numerically controlled (NC) machines connected by an automated materials handling all systems under computer control. Such arrangements are set up to process a wide variety of parts especially with low to medium volume of demand. FMS gives maximum flexibility and efficiency for production of different parts together. Shared usage of resources is commonplace to achieve such advantages. Pooling identical machines in a group and providing multiple operation/tool loading support effective ways of allowing alternate part routing practices. However, as an automated manufacturing system involves simultaneous machining of various part types with the availability of multiple routes for each, planning for and implementing shop procedures to support these operations become a complex task.

Loading of multiple part types for simultaneous machining in a multiple machine flexible manufacturing cell was performed by solving a mathematical programming model. This was accompanied by a cyclic routing policy. The purpose in cyclic routing of pallets to machines was to preserve the ideal synchronization all through a month's operation. A shop simulation model was constructed to validate the suggested cyclic routing and to supply more realistic parameters to the mathematical programming model. The two models worked in an iterative manner until the discrepancy in observed versus supplied values came within an acceptable range. Encouraging results were obtained, as all simulation runs indicated close tracking (within 2–3%) of the ideal proportions.