Research On Integrated Scheduling Algorithms Of Second Workshops With Pre-start Machine

With the development of science and technology,users' personalized demands for products are increasing day by day.The large-scale flow operations in the traditional manufacturing industry can no longer meet the personalized requirements of people in today's era.The integrated scheduling of small batch processing and assembly processing has become a new topic in scheduling research.Although the research on the problem of integrated scheduling has achieved many results,there is no research on the problem of integrated scheduling with pre-start equipment.In view of the fact that there is no consideration of the existence of pre-start equipment in the current integrated scheduling research,and the effect of the prestart time on the overall processing time is ignored,the single-shop integrated scheduling algorithm with pre-start equipment is first proposed.This algorithm adopts the proposed pre-start long path priority strategy when the pre-start equipment is in the idle state,and uses the proposed pre-start short path priority strategy when the pre-start equipment is in the working state to improve the parallelization of the pre-start equipment and reduce the equipment number of prestarts;through the proposed adjustable sequence determination strategy,determine the sequence of processes that cause the equipment to generate idle time periods;adopting the proposed adjustable sequence process adjustment strategy,the processing time of the predecessor process that causes the equipment to be idle is adjusted according to the sequence to improve the utilization rate of the equipment.An example shows that this algorithm solves the single-shop integrated scheduling problem with pre-start equipment,and has certain theoretical and practical significance.Aiming at the problem of symmetric two-shop integrated scheduling with prestart equipment,a symmetric two-shop integrated scheduling algorithm with pre-start equipment is proposed.The algorithm adopts the workshop selection strategy.When both workshops are idle,the process is processed in the same workshop as the latest end of the process immediately before.The other processes use the processing time gap to complete the migration and use the migration time to schedule the pre-start equipment the pre-startup time will ultimately reduce the waste of time;this algorithm proposes a strategy for adjusting the equipment idle time period to drive the process.It uses the equipment idle time period to drive the unprocessed processes of the equipment.These processes are used as the root nodes to form part of the processing tree.In addition,the part of the processing tree with the shortest critical path is given priority to the leaf nodes on the critical path,so that the process can reach the idle equipment as early as possible,reducing the idle time of the equipment and improving the utilization rate of the equipment.Aiming at the problem of two-shop integrated scheduling with asymmetric pre-start equipment,a two-shop integrated scheduling algorithm with asymmetric pre-start equipment is proposed.This algorithm analyzes the selection of the process to the processing workshop under the condition of asymmetric pre-start equipment resources,and analyzes the minimum number of migrations of the process in different situations,and proposes a strategy of workshop migration selection with asymmetric pre-start equipment.This strategy solves the problem of selecting the processing workshop when the process is processed in the two workshops.The workshop processing procedure with the ready time immediately after the procedure is selected.When the preparation time of the immediate procedure is the same,the workshop where the process is located is prioritized Processing,ultimately achieve the purpose of reducing the number of process migration.And use the process migration time to pre-start the pre-start equipment to achieve the purpose of saving time.This thesis studies and analyzes the integrated scheduling problem with prestart equipment,and proposes the integrated scheduling algorithm with pre-start equipment,the symmetric two-shop integrated scheduling algorithm with pre-start equipment,and the asymmetric two-shop scheduling algorithm with pre-start equipment.An example shows that the algorithm proposed in this thesis solves the problem of integrated scheduling related to the presence of pre-start equipment,and has certain theoretical and practical significance.