2 What is schedulingIn a production system, it is the timing and sequencing of the use of specific resources in the system and is the final step in the decision making process of an organization before the actual transformation processes begin.
3 Scheduling Manufacturing Operations Build AA DoneBuild BB DoneBuild CC DoneBuild DShipJANFEBMARAPRMAYJUNOn time!High-volumeIntermediate- volumeLow-volumeService operations
4 High-Volume SystemsFlow system: High-volume system with Standardized equipment and activitiesFlow-shop scheduling: Scheduling for high-volume flow systemWork Center #1Work Center #2Output
5 High-Volume Success Factors Process and product designPreventive maintenanceRapid repair when breakdown occursOptimal product mixesMinimization of quality problemsReliability and timing of supplies
6 Intermediate-Volume Systems Outputs are between standardized high-volume systems and made-to-order job shopsEconomic run size:
7 Scheduling Low-Volume Systems Loading - assignment of jobs to process centersSequencing - determining the order in which jobs will be processed
8 LoadingGantt chart - used as a visual aid for loading and scheduling
9 Assignment Problem Jobs Workers Assigning jobs to workers. There is a cost associated with a worker completing a certain job. The objective is to finish all the jobs by the workers so that the total cost is minimized.An optimal solution can be found by the Hungarian Method.
10 SequencingSequencing: Determine the order in which jobs at a work center will be processed.Workstation: An area where one person works, usually with special equipment, on a specialized job.
11 SequencingPriority rules: Simple heuristics used to select the order in which jobs will be processed.Job time: Time needed for setup and processing of a job.Everything is #1 Priority
12 Priority Rules FCFS - first come, first served SPT - shortest processing timeDD - due dateCR - critical ratioS/O - slack per operationRush - emergencyTop Priority
13 Two Work Center Sequencing Johnson’s Rule: technique for minimizing completion time for a group of jobs to be processed on two machines or at two work centers.Minimizes total idle timeSeveral conditions must be satisfied
14 Johnson’s Rule Conditions Job time must be known and constantJob times must be independent of sequenceJobs must follow same two-step sequenceJob priorities cannot be usedAll units must be completed at the first work center before moving to second
15 Scheduling Service Operations Appointment systemsControls customer arrivals for serviceReservation systemsEstimates demand for serviceScheduling the workforceManages capacity for serviceScheduling multiple resourcesCoordinates use of more than one resource
16 Service Operation Problems Cannot store or inventory servicesCustomer service requests are randomScheduling service involvesCustomersWorkforceEquipment