Session 7 Managing The Master Scheduling Process - APICS Master Planning of Resources

1、Master Planning of Resources Session 7 Managing the Master Scheduling Process Visual 7-2 Master Planning of Resources, ver. 2.0 December 2001 Master Planning of Resources Session 1: The Business Planning Process Session 2: Forecasting Demand Session 3: Demand Management and Customer Service Session

2、4: Distribution Planning Session 5: The Sales and Operations Planning Process Session 6: The Master Scheduling Process Session 7: Managing the Master Scheduling Process Session 8: Measuring Performance and Validating the Plan Visual 7-3 Master Planning of Resources, ver. 2.0 December 2001 Session 7

3、Objectives lDescribe the tradeoffs of inventory, production, customer service, and profitability lDescribe time fences and their uses lDescribe hedges and how they are used in master scheduling lDescribe the rough-cut capacity planning process and its uses lIdentify the uses of a multilevel master p

4、roduction schedule and show how it is calculated lDescribe the final assembly schedule and how it is used Visual 7-4 Master Planning of Resources, ver. 2.0 December 2001 Master Scheduling Production Plan Master Scheduling Master Production Schedule Rough-Cut Capacity Planning Visual 7-5 Master Plann

5、ing of Resources, ver. 2.0 December 2001 Data Sources for Master Scheduling Function Data provided SALES and OPERATIONS PLANNING PRODUCTION PLAN Engineering New product introduction Sales / Marketing Sales forecasts Management Customer service targets FinanceExpense budgets MaterialsSupply constrain

6、ts and Inventory availability ProductionProduction constraints and Maintenance schedules Human ResourcesWorkforce constraints Visual 7-6 Master Planning of Resources, ver. 2.0 December 2001 Common Changes in Demand lCustomer schedule changes lRush orders lOrder cancellations lChanges to specificatio

7、ns Visual 7-7 Master Planning of Resources, ver. 2.0 December 2001 Common Changes in Supply lNonconformance to schedule Production downtime Capacity availability lNonconformance to specifications Scrap Effect of quality Visual 7-8 Master Planning of Resources, ver. 2.0 December 2001 Engineering Chan

8、ges lMandatory or immediate lPhased-in or optional lProcess Set up a review board Determine the procedure for instituting change Set effective dates Ensure change process deals with multiple items Assess the cost and impact of the change Maintain the status for each revision Visual 7-9 Master Planni

9、ng of Resources, ver. 2.0 December 2001 Managing Change lIs the change necessary? lIs the change feasible? lAre resources available? lWhat are the costs, risks, and benefits? Visual 7-10 Master Planning of Resources, ver. 2.0 December 2001 Tradeoffs in Master Scheduling Customer service Customer ser

10、vice Production savings Purchase savings Inventory investment Profitability Inventory investment Inventory investment Visual 7-11 Master Planning of Resources, ver. 2.0 December 2001 Planned Orders Firm Planned Orders Released Orders Production OrdersPurchase Orders Types of Supply Orders Visual 7-1

11、2 Master Planning of Resources, ver. 2.0 December 2001 MPS Time Zones DEMAND TIME Frozen Customer Order Backlog Forecast Impact of change FlexibleFree $ Visual 7-13 Master Planning of Resources, ver. 2.0 December 2001 Defining Time Fence Policies Time Demand (DTF) Planning (PTF) Emergency Changes On

12、ly Tradeoff Changes Only Constrained by Production Plan Time Fences FrozenFlexibleFree Current Date Visual 7-14 Master Planning of Resources, ver. 2.0 December 2001 Creating Firm Planned Orders Time DTF PTF Released Orders for Customer Orders (little risk) Firm Planned Orders for Customer Orders Pla

13、nned Orders based on Forecasts Current Date Risk Area FrozenFlexibleFree Visual 7-15 Master Planning of Resources, ver. 2.0 December 2001 Safety Factors Safety Stock Volume Hedge Mix Hedge Safety Lead Times Safety Capacity Visual 7-16 Master Planning of Resources, ver. 2.0 December 2001 Hedges A hed

14、ge is a scheduled quantity to protect against uncertainty in demand or supply. The hedge is similar to safety stock, except that a hedge has the dimension of timing as well as amount. lA volume hedge or market hedge permits authorized overplanning by the master scheduler. lA product mix hedge is an

15、approach where several interrelated optional items are overplanned. Visual Master Planning of Resources, ver. 2.0 December 2001 Mixed-Model Production R G R B R G R B R G Product Mix Red 50% Green 30% Blue 20% Daily Volume 10,000 units Production Sequence 7-17 Visual Master Planning of Resources, ve

16、r. 2.0 December 2001 Rough-Cut Capacity Planning (RCCP) Converts the master production schedule into load requirements for critical resource constraints Comparison to available or demonstrated capacity is usually done for each critical resource The comparison assists the master scheduler in establis

17、hing a feasible master production schedule 7-18 Visual Master Planning of Resources, ver. 2.0 December 2001 Benefits of RCCP lUses profiles of resource, avoids the need for detailed routings lA quick and simple tool to assess the feasibility and can be applied relatively quickly for easy validation

18、lCan be performed as often as necessary prior to the execution of the master production schedule lCan be used to assess the impact of any proposed changes prior to implementing them 7-19 Visual Master Planning of Resources, ver. 2.0 December 2001 Limitations of RCCP lOnly considers critical workcent

19、ers lMay not consider the effect of job sequence or job setup time dependency lMay ignore the work in process lLittle value as an intermediate or long-term planning tool 7-20 Visual Master Planning of Resources, ver. 2.0 December 2001 The Rough-Cut Capacity Planning Process Identify capacity of crit

20、ical workcenters Develop profiles of resources Calculate load on workcenters Compare to capacity available 1 2 3 4 5 Master Production Schedule 6 Develop corrective plans Identify over-and under-loading 7-21 Visual Master Planning of Resources, ver. 2.0 December 2001 RCCP Example Start With the Mast

21、er Production Schedule Week Product 32 33 34 35 Total 1 180180360 2180 36216 3144144 Totals180180180180720 Identify the rough-cut capacity profile for each product (assembly of products 2 and 3 in week 35) Product Units Wk.35 Std Hrs/Unit Total Hrs. 2 36.29410.58 3144.21030.24 40.82 7-22 Visual Mast

22、er Planning of Resources, ver. 2.0 December 2001 RCCP Example Then calculate the rough-cut capacity requirements (assembly WC) Load and Capacity in hours/week 32333435Total Standard Hours61.5661.5652.9240.82216.86 Efficiency.95.95.95.95 Required load hours64.8064.8055.7142.97228.28 Capacity availabi

23、lity58.2558.2558.2558.25233.00 Over (under) load6.556.55(2.54)(15.28)(4.72) 7-23 Visual Master Planning of Resources, ver. 2.0 December 2001 Load Profile Example 3233343536 Planning Time Fence Demand Time Fence Uncommitted Capacity Available Capacity 80 70 60 50 40 30 20 10 0 Hours Required Capacity

24、: All Released Orders All Firm Planned Orders All Planned Orders Assembly Work Center Note: The schedule prior to period 32 is frozen 7-24 Visual Master Planning of Resources, ver. 2.0 December 2001 Possible Solutions Overloading Overtime Extra shifts Transfer people Reroute work Subcontract Hire te

25、mporary help Install more equipment Add additional capacity 7-25 Visual Master Planning of Resources, ver. 2.0 December 2001 Possible Solutions Underloading Increase sales demand Use time for training Use time for maintenance Reduce shifts Transfer people Reroute work Reduce subcontracting Lay off t

26、emporary help Reduce capacity Temporary layoff 7-26 Visual Master Planning of Resources, ver. 2.0 December 2001 7-27 Revised MPS/RCCP Report MPSWeek Product32333435Total 116116138360 214274216 3_144144 161161180218720 OLD MPS Week Product32333435Total 1180180360 218036216 3_144144 180180180180720 Vi

27、sual Master Planning of Resources, ver. 2.0 December 2001 RCCP Report (Assembly Workcenter) Load and Capacity (in hours/week) Revised MPS/RCCP Report (cont.) 7-28 Product 32 33 34 35 155.0655.0613.00 241.7521.76 330.24 Standard Hours55.0655.0654.7552.00 Efficiency.95.95.95.95 Total required57.9657.9

28、657.6354.74 Capacity available58.2558.2558.2558.25 Over (under) load(.29)(.29)(.62)(3.51) Visual 7-29 Master Planning of Resources, ver. 2.0 December 2001 Differences between RP and RCCP Resource Planning lValidates the production plan lOn a monthly basis lFor all potentially constraining resources

29、lOver the medium- to long-term planning horizon Rough-Cut Capacity Planning lValidates the master production schedule lOn a daily/weekly basis lFor identified critical workcenters lOver the short- to medium-term planning horizon Visual Master Planning of Resources, ver. 2.0 December 2001 Multilevel

30、Master Scheduling lAllows any level in an end items bill of material to be master scheduled lRequirements are received from both independent and dependent demand sources 7-30 Visual Master Planning of Resources, ver. 2.0 December 2001 Top level Middle level Third level Process industryPackaging line

31、sBulk process (e.g., chemicals,final assemblyscheduling pharmaceuticals,schedule (FAS)(MPS) cosmetics) Assemble-to-orderCustomer orders Product familiesProduct modules (e.g., automobiles,(FAS)(MPS)and options forklifts)(MPS-modular) Make-to-orderCustomer orders Product families (e.g., built-in(FAS)o

32、r raw materials cabinets, titanium(MPS) aircraft parts) Source: Adapted from Master Planning Certification Review Course, APICS, 1988 Multilevel Master Scheduling 7-31 Visual Master Planning of Resources, ver. 2.0 December 2001 Two-Level Master Scheduling Example 7-32 Body 1.0 4 Cyl 0.70 6 Cyl 0.40

33、Engine 1.0 Manual 0.35 Auto 0.75 Transmission 1.0 Radial 0.85 Bias 0.20 Tires 4.0 Compact Car Assembly (Top-Level) Product Planning Subassemblies Master Schedule Level % Consumption Source: Adapted from Williams, B.R., Manufacturing for Survival (Addison Wesley, 1996). Visual Master Planning of Reso

34、urces, ver. 2.0 December 2001 7-33 Two-Level Master Scheduling Example (Cont.) Phase 1: Before Receiving Customer Orders WEEK LEVEL 1: Compact Car1234 Production Plan100 1005050 Customer Orders Available to Promise (ATP)100 1005050 MPS100 1005050 WEEK LEVEL 2: 4-Cylinder Option (70%)1234 Production

35、Forecast70703535 Customer Orders Projected Available Balance00000 Available to Promise (ATP)70703535 MPS70703535 Source: Adapted from Williams, B.R., Manufacturing for Survival (Addison Wesley, 1996). Visual Master Planning of Resources, ver. 2.0 December 2001 Two-Level Master Scheduling Example (Co

36、nt.) 7-34 Phase 2: On Receiving Customer Orders WEEK LEVEL 1: Compact Car1234 Production Plan100 1005050 Customer Orders60405040 Available to Promise (ATP)4060010 MPS100 1005050 WEEK LEVEL 2: 4-Cylinder Option (70%)1234 Production Forecast284207 Customer Orders30202020 Projected Available Balance012

37、203543 Available to Promise (ATP)40501515 MPS70703535 Source: Adapted from Williams, B.R., Manufacturing for Survival (Addison Wesley, 1996). Visual Master Planning of Resources, ver. 2.0 December 2001 Final Assembly Schedule (FAS) A schedule for finishing operations Based on customer orders For cus

38、tomer specific products MTO/ATO/ETO environment Constrained by material and capacity 7-35 Visual Master Planning of Resources, ver. 2.0 December 2001 FAS and MPS in MTO/ATO/ETO 7-36 Final Assembly Schedule (FAS) Master Production Schedule (MPS) Time SpanPlanning (short)Planning time fence (long) Dem

39、and SourceCustomer ordersForecast Product levelFinished end itemSemifinished assemblies and components ConstraintsMPSProduction plan Planning periodDays or shiftsWeeks or months Visual Master Planning of Resources, ver. 2.0 December 2001 The Final Assembly Process Collect order specifications Determine total capacity Determine MTO & ATO components Develop FAS 1 2 3 4 Master Production Schedule Link to MPS (optional) 5 7-37 Visual Master Planning of Resources, ver. 2.0 December 2001 Formulating the FAS lLau