Operations management heizer 6e ch15

Operations Management Chapter 15 – Short-Term Scheduling PowerPoint presentation to accompany Heizer/Render Principles of Operations Management, 6e Operations Management, 8e © 2006 Prentice Hall, Inc Hall, Inc © 2006 Prentice 15 – Outline  Global Company Profile: Delta Airlines  The Strategic Importance Of ShortTerm Scheduling  Scheduling Issues  Forward and Backward Scheduling  Scheduling Criteria © 2006 Prentice Hall, Inc 15 – Outline – Continued  Scheduling Process-Focused Facilities  Loading Jobs  Input-Output Control  Gantt Charts  Assignment Method © 2006 Prentice Hall, Inc 15 – Outline – Continued  Sequencing Jobs  Priority Rules for Dispatching Jobs  Critical Ratio  Sequencing N Jobs on Two Machines: Johnson’s Rule  Limitations Of Rule-Based Dispatching Systems  Finite Capacity Scheduling (FCS) © 2006 Prentice Hall, Inc 15 – Outline – Continued  Theory Of Constraints  Bottlenecks  Drum, Buffer, Rope  Scheduling Repetitive Facilities  Scheduling Services  Scheduling Service Employees with Cyclical Scheduling © 2006 Prentice Hall, Inc 15 – Learning Objectives When you complete this chapter, you should be able to: Identify or Define:  Gantt charts  Assignment method  Sequencing rules  Johnson’s rule  Bottlenecks © 2006 Prentice Hall, Inc 15 – Learning Objectives When you complete this chapter, you should be able to: Describe or Explain:  Scheduling  Sequencing  Shop loading  Theory of constraints © 2006 Prentice Hall, Inc 15 – Delta Airlines  About 10% of Delta’s flights are disrupted per year, half because of weather  Cost is $440 million in lost revenue, overtime pay, food and lodging vouchers  The $33 million Operations Control Center adjusts to changes and keeps flights flowing  Saves Delta $35 million per year © 2006 Prentice Hall, Inc 15 – Strategic Importance of Short-Term Scheduling  Effective and efficient scheduling can be a competitive advantage  Faster movement of goods through a facility means better use of assets and lower costs  Additional capacity resulting from faster throughput improves customer service through faster delivery  Good schedules result in more reliable deliveries © 2006 Prentice Hall, Inc 15 – Scheduling Issues  Scheduling deals with the timing of operations  The task is the allocation and prioritization of demand  Significant issues are  The type of scheduling, forward or backward  The criteria for priorities © 2006 Prentice Hall, Inc 15 – 10 Scheduling Repetitive Facilities  Level material use can help repetitive facilities  Better satisfy customer demand  Lower inventory investment  Reduce batch size  Better utilize equipment and facilities © 2006 Prentice Hall, Inc 15 – 63 Scheduling Repetitive Facilities  Advantages include: Lower inventory levels Faster product throughput Improved component quality Reduced floor-space requirements Improved communications Smoother production process © 2006 Prentice Hall, Inc 15 – 64 Scheduling Services Service systems differ from manufacturing Manufacturing Schedules machines and materials Inventories used to smooth demand Machine-intensive and demand may be smooth Scheduling may be bound by union contracts Few social or behavioral issues © 2006 Prentice Hall, Inc Services Schedule staff Seldom maintain inventories Labor-intensive and demand may be variable Legal issues may constrain flexible scheduling Social and behavioral issues may be quite important 15 – 65 Scheduling Services  Hospitals have complex scheduling system to handle complex processes and material requirements  Banks use a cross-trained and flexible workforce and part-time workers  Airlines must meet complex FAA and union regulations and often use linear programming to develop optimal schedules  24/7 Operations use flexible workers and variable schedules © 2006 Prentice Hall, Inc 15 – 66 Demand Management  Appointment or reservation systems  FCFS sequencing rules  Discounts or other promotional schemes  When demand management is not feasible, managing capacity through staffing flexibility may be used © 2006 Prentice Hall, Inc 15 – 67 Scheduling Service Employees With Cyclical Scheduling  Objective is to meet staffing requirements with the minimum number of workers  Schedules need to be smooth and keep personnel happy  Many techniques exist from simple algorithms to complex linear programming solutions © 2006 Prentice Hall, Inc 15 – 68 Cyclical Scheduling Example Determine the staffing requirements Identify two consecutive days with the lowest total requirements and assign these as days off Make a new set of requirements subtracting the days worked by the first employee Apply step to the new row Repeat steps and until all requirements have been met © 2006 Prentice Hall, Inc 15 – 69 Cyclical Scheduling Example Employee M T W T F S S 5 3 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 70 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 71 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 72 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Employee 2 2 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 73 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Employee 2 2 Employee 1 2 2 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 74 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Employee 2 2 Employee 1 2 2 Employee 1 1 1 Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 75 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Employee 2 2 Employee 1 2 2 Employee 1 1 1 Employee Capacity Excess Capacity © 2006 Prentice Hall, Inc 15 – 76 Cyclical Scheduling Example M T W T F S S Employee 5 3 Employee 4 3 Employee 3 3 Employee 2 2 Employee 1 2 2 Employee 1 1 1 Employee Capacity 5 4 Excess Capacity 0 0 © 2006 Prentice Hall, Inc 15 – 77 ... Cost is $440 million in lost revenue, overtime pay, food and lodging vouchers  The $33 million Operations Control Center adjusts to changes and keeps flights flowing  Saves Delta $35 million... deliveries © 2006 Prentice Hall, Inc 15 – Scheduling Issues  Scheduling deals with the timing of operations  The task is the allocation and prioritization of demand  Significant issues are ... Figure 15.2 © 2006 Prentice Hall, Inc 15 – 22 Input-Output Control Example Options available to operations personnel include: Correcting performances Increasing capacity Increasing or reducing