【正文】 2023 Qi Chao. All rights reserved. 86 LongRange Planning ? Planning range ? Around si。2023 Qi Chao. All rights reserved. 84 MRP II ?Manufacturing resources planning addresses deficiencies of MRP ?Bring together other functions subsumed by MRP including demand management, forecasting, capacity planning, master production scheduling, roughcut capacity planning, capacity requirements planning, dispatching, an input/output control Copyright 169。2023 Qi Chao. All rights reserved. 82 Hubbell Lighting Case Before MRP Implementation ? Less than 75% of orders pleted on time After MRP Implementation ? 97% of orders pleted on time ? 2% of orders pleted with 1 to 2 days after due date Copyright 169。2023 Qi Chao. All rights reserved. 80 Part B 1 2 3 4 5 6 7 8 Gross requirements 14 49 Scheduled receipts 14 Adjusted SRs Projected onhand 2 2 2 2 2 2 47 Net requirements 47 Planned order receipts (FOP=5w) 47 Planned order releases 47 MRP calculations for item B after change with FPO Copyright 169。2023 Qi Chao. All rights reserved. 78 Part A 1 2 3 4 5 6 7 8 Gross requirements 2 23 3 5 1 3 4 50 Scheduled receipts Firm planned orders 14 Projected onhand 28 26 3 14 9 8 5 1 49 Net requirements 49 Planned order receipts (FOP=5w) [14] 49 Planned order releases [14] 49 MRP calculations for item A after change with FPO Copyright 169。2023 Qi Chao. All rights reserved. 76 How to do with system nervousness? ? Frozen zone ? An initial number of periods in the MPS in which changes are not permitted ? Early planned order releases are the ones in which change is most disruptive. ? Time fences ? The earliest time fence is absolutely frozen ? The next fence is restricted but less restricted… ? Firm planned orders ? FPO fix early planned order releases Copyright 169。2023 Qi Chao. All rights reserved. 74 Part B 1 2 3 4 5 6 7 8 Gross requirements Scheduled receipts 14 Adjusted SRs Projected onhand 2 Net requirements Planned order receipts (FOP=5w) Planned order releases MRP calculations for item B after change in demand Copyright 169。2023 Qi Chao. All rights reserved. 72 Part A 1 2 3 4 5 6 7 8 Gross requirements 2 23 3 5 1 3 4 50 Scheduled receipts Adjusted SRs Projected onhand 28 Net requirements Planned order receipts (FOP=5w) Planned order releases MRP calculations for item A after change in demand Copyright 169。2023 Qi Chao. All rights reserved. 70 Part A 1 2 3 4 5 6 7 8 Gross requirements 2 24 3 5 1 3 4 50 Scheduled receipts Adjusted SRs Projected onhand 28 26 2 1 Net requirements 1 5 1 3 4 50 Planned order receipts (FOP=5w) 14 50 Planned order releases 14 50 MRP calculations for item A before change in demand Copyright 169。2023 Qi Chao. All rights reserved. 68 Problems in MRP ?System nervousness ? When a small change in the master production schedule results in a large change in planned order releases. ? This can lead time strange effects. For instance as we demonstrate with the following example, it is actually possible for a decrease in demand to cause a formerly feasible MRP plan to bee infeasible Copyright 169。2023 Qi Chao. All rights reserved. 56 Part 100 1 2 3 4 5 6 7 8 Requirement from A 90 60 Requirement from 500 25 15 Gross requirements 25 15 90 60 Scheduled receipts Adjusted SRs Projected onhand 40 15 0 Net requirements 90 60 Planned order receipts (lotforlot) 90 60 Planned order releases 90 60 57 Part 300 1 2 3 4 5 6 7 8 Required from B 35 30 15 Required from 100 90 60 Gross requirements Scheduled receipts Adjusted SRs Projected onhand 50 Net requirements Planned order receipts (lot for lot) Planned order releases 58 Part 300 1 2 3 4 5 6 7 8 Required from B 35 30 15 Required from 100 90 60 Gross requirements 125 90 15 Scheduled receipts 100 Adjusted SRs 100 Projected onhand 50 50 25 25 65 Net requirements 65 15 Planned order receipts (lot for lot) 65 15 Planned order releases 65 15 Copyright 169。2023 Qi Chao. All rights reserved. 54 Part 500 1 2 3 4 5 6 7 8 Gross requirements 35 30 15 Scheduled receipts Adjusted SRs Projected onhand 40 40 5 5 25 Net requirements 25 15 Planned order receipts (lotforlot) 25 15 Planned order releases 25* 15 Copyright 169。2023 Qi Chao. All rights reserved. 52 Part B 1 2 3 4 5 6 7 8 Gross requirements 10 15 10 20 20 15 15 15 Scheduled receipts Adjusted SRs Projected onhand 40 30 15 5 15 Net requirements 15 20 15 15 15 Planned order receipts (FOP=2w) 35 30 15 Planned order releases 35 30 15 Copyright 169。2023 Qi Chao. All rights reserved. 50 Part Number Current Onhand SRs Lotsizing rule Lead time Due Quantity B 40 0 FOP (2w) 2 w 100 40 0 LFL 2 w 300 50 2 100 LFL 1 w 500 40 0 LFL 4 w Copyright 169。2023 Qi Chao. All rights reserved. 48 Part A 1 2 3 4 5 6 7 8 Gross requirements 15 20 50 10 30 30 30 30 Scheduled receipts 10 10 100 Adjusted SRs Projected onhand 20 Net requirements Planned order receipts (FOP=2w) Planned order releases (LT=2) Copyright 169。2023 Qi Chao. All rights reserved. 46 PPB Quantity for Period 2 Setup cost ($) Partperiods Inventory cost ($) h=2 15 150 0 0 60 150 45*1=45 90 85 150 45+25*4=145 290 Quantity for period 6 Setup cost ($) Partperiods Inventory cost ($) h=2 25 150 0 0 40 150 15*1=15 30 60 150 15+20*2=55 110 75 150 55+15*3=100 200 Copyright 169。2023 Qi Chao. All rights reserved. 44 Lotsizing Rules ? Fixed Order Period (FOP) ? If you are going to produce in pe