Tham khảo tài liệu 'multiprocessor scheduling part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 320 Multiprocessor Scheduling Theory and Applications LOAD UNLOAD PROCESS Parameter Value Loading unloading parts to from pallets min. Moving pallets to load unload storage buffers min. MATERIAL HANDLING SYSTEM Parameter Value Number of AGVs 1 Transfer time between the stations min. OPERATORS Parameter Value Number of operators 8 Operator transfer time between workstations min For each product type Tables 1 and 2 show the operational sequences with required resources and processing times without setup times. Operations Machine required - Processing time O-l M-l min. M-3 min. O-2 M-2 min. M-4 min. O-3 M-5 9 min. M-6 min. M-7 6 min. M-3 min. O-4 M-8 2 min. O-5 M-9 . Table 1. Process plan of product type 1 P1 Operations Machine required - Processing time O-l M-3 min O-2 M-4 min. O-3 M-5 13 min. M-6 min. for P-2 min. for P3 M-3 min. O-4 M-8 2 min. O-5 M-9 . Table 2. Process plan of product type 2 and 3 P2 and P3 Ten independent replications for each dispatching strategies were run for operating minutes 125 days with three 8 hr shifts during the simulation of the PN model. In each run the shop is continuously loaded with job-orders that are numbered on arrival and each run produced one observation for each performance measure. Different random number seeds were used to prevent correlation between the parallel runs of the factorial experiment. In A Heuristic Rule-Based Approach for Dynamic Scheduling of Flexible Manufacturing Systems 321 order to ascertain when the system reaches a steady state the shop parameters such as mean flow time of jobs and utilization level of machines were observed and it has been found that the system became stable after a warm-up period of simulated minutes 30 days with three 8 hr shifts . Thus for each replication the first minutes was discarded to remove the effect of the start-up condition which was an idle and empty state. Performance of the .
