SchedulingHow Scheduling fits the Operations Management PhilosophyAir New ZealandSlide 4Performance MeasuresGantt ChartsSlide 7Slide 8Scheduling Customer DemandScheduling EmployeesSlide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Operations SchedulingSlide 20Job Shop DispatchingSlide 22Slide 23Scheduling Jobs for One WorkstationSlide 25Slide 26Slide 27Comparing the EDD and SPT RulesSlide 29Slide 30Slide 31Priority Rule SummaryScheduling Jobs for Multiple WorkstationsJohnson’s RuleSlide 35Slide 36Labor-limited EnvironmentsLinking Operations Scheduling to the Supply ChainSlide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47© 2007 Pearson EducationSchedulingSchedulingChapter 16Chapter 16© 2007 Pearson EducationHow Scheduling fits the Operations Management Philosophy Operations As a Competitive WeaponOperations StrategyProject ManagementProcess StrategyProcess AnalysisProcess Performance and QualityConstraint ManagementProcess LayoutLean SystemsSupply Chain StrategyLocationInventory ManagementForecastingSales and Operations PlanningResource PlanningScheduling© 2007 Pearson EducationAir New ZealandFlight and crew scheduling is a complex process.Scheduling begins with a five-year market plan.This general plan is further refined to a three-year plan, and put into an annual budget in which flight segments have specific departure and arrival times.Crew availability must be matched to the flight schedule. Two types of crews–pilots and attendants–each comes with its own set of constraints.Sophisticated optimization models are used to design generic minimum-cost schedules.© 2007 Pearson EducationSchedulingScheduling: The allocation of resources over time to accomplish specific tasks.Demand scheduling: A type of scheduling whereby customers are assigned to a definite time for order fulfillment.Workforce scheduling: A type of scheduling that determines when employees work.Operations scheduling: A type of scheduling in which jobs are assigned to workstations or employees are assigned to jobs for specified time periods.© 2007 Pearson EducationPerformance MeasuresJob flow time: The amount of time a job spends in the service or manufacturing system. Also referred to as throughput time or time spent in the system, including service.Makespan: The total amount of time required to complete a group of jobs.Past due (Tardiness): The amount of time by which a job missed its due date or the percentage of total jobs processed over some period of time that missed their due dates.Work-in-process (WIP) inventory: Any job that is waiting in line, moving from one operation to the next, being delayed, being processed, or residing in a semi-finished state.Total inventory: The sum of scheduled receipts and on-hand inventories.Utilization: The percentage of work time that is productively spent by an employee or machine.© 2007 Pearson EducationGantt ChartsGantt chart: Used as a tool to monitor the progress of work and to view the load on workstations. The chart takes two basic forms: (1) the job or activity progress chart, and (2) the workstation chart. The Gantt progress chart graphically displays the current status of each job or activity relative to its scheduled completion date.The Gantt workstation chart shows the load on the workstations and the nonproductive time.© 2007 Pearson EducationGantt Progress ChartGantt Progress ChartPlymouthFordPontiacJob 4/20 4/22 4/23 4/24 4/25 4/264/214/17 4/18 4/19Current Current date date Scheduled activity timeActual progressStart activityFinish activityNonproductive timeGantt Progress Chart for an Auto Parts Company© 2007 Pearson EducationGantt Workstation Chart Gantt Workstation Chart Gantt Workstation Chart for Hospital Operating Rooms© 2007 Pearson EducationScheduling Customer DemandThree methods are commonly used to schedule customer demand: (1) Appointments assign specific times for service to customers.(2) Reservations are used when the customer actually occupies or uses facilities associated with the service.(3) Backlogs:•The customer is given a due date for the fulfillment a product order, or •Allow a backlog to develop as customers arrive at the system. Customers may never know exactly when their orders will be fulfilled© 2007 Pearson EducationScheduling EmployeesRotating schedule: A schedule that rotates employees through a series of workdays or hours.Fixed schedule: A schedule that calls for each employee to work the same days and hours each week.Constraints: The technical constraints imposed on the workforce schedule are the resources provided by the staffing plan and the requirements placed on the operating system. Other constraints, including legal and behavioral considerations, also can be imposed.© 2007 Pearson EducationDayDayMMTTWWThThFFSSSuSuNumber of employeesNumber of employees6644889910103322Required employeesRequired employeesThe Amalgamated Parcel Service is open 7 days a week. The schedule of requirements is:The manager needs a workforce schedule that provides two consecutive days off and minimizes the amount of total slack capacity. To break ties in the selection of off days, the scheduler gives preference to Saturday and Sunday if it is one of the tied pairs. If not, she selects one of the tied pairs arbitrarily.Workforce SchedulingExample 16.1© 2007 Pearson EducationRequired employeesRequired employeesDayDayMMTTWWThThFFSSSuSuNumber of employeesNumber of employees66448899 10* 10* 3322EmployeeEmployee11 X XXXXXXXXXWorkforce SchedulingExample 16.1 Steps 1 & 2Step 1. Find all the pairs of consecutive days that exclude the maximum daily requirements. Select the unique pair that has the lowest total requirements for the 2 days.Friday contains the maximum requirements (10), and the pair S–Su has the lowest total requirements. Therefore, Employee 1 is scheduled to work Monday through Friday. Step 2. If a tie occurs, choose one of the tied pairs or ask the employee to make a choice.© 2007 Pearson EducationRequired employeesRequired employeesStep 3. Subtract the requirements satisfied by the Employee 1 from the net requirements for each day the employee is to work and repeat step one.Again the pair S–Su has the lowest total requirements. Therefore, Employee 2 is scheduled to work Monday through Friday.DayDayMMTTWWThThFFSSSuSuNumber of employeesNumber of