Tham khảo tài liệu 'multiprocessor scheduling part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 410 Multiprocessor Scheduling Theory and Applications processing sequence is reversed and the schedule time frame is reversed back to forward time frame. The backward scheduling considers inserted idle times between processing of orders. Forward scheduling is a straightforward method that schedules jobs one by one from the beginning time of the planning period. The main objective is to make sure that each job can meet its due date. The forward scheduling methodology presented in the previous section does not minimize AWT effectively. This is overcome by adopting a backward approach that inserts idle times between order groups. The last flight s departure time determines the completion time for the last order to be scheduled in the assembly in the planning period. To minimize order earliness before transportation the favorable completion time for each order is their corresponding flight departure time. Hence within each group orders are scheduled one by one without inserted idle time in backward direction from the order group s due-date. Once the completion time for the last order to be scheduled in each group is determined the release times for the preceding orders is calculated by subtracting its processing times from the release time of the succeeding orders. Idle times are inserted only between order groups. When the release time of the first order in the succeeding group is later than the current order group s due date idle time is inserted between the two groups. Thus the last job of the current order group is scheduled to complete at the corresponding flight departure time. The pseudo code description of the backward scheduling logic is presented below If job i is the last job in flight j then If flight j is the last flight then Release time job i flight j Departure time flight j - Processing time job i flight j Else If Release time the first job fight j 1 is earlier than Departure time flight j then Release time job i flight j Release time the first job .