Manufacturing Systems MRP Tutorial 2 Developed by: Alex J. Ruiz-Torres, Ph.D.

Objectives/ Structure This tutorial will illustrate all the steps required to develop a multiple item MRP schedule. MRP tables Production Plan It is assumed that the student already reviewed and has a good understanding of the concepts presented in MRP Tutorial 1

Product Information and Requirements Develop an MRP schedule and final production plan Two End Items (Two End Products) Large unit Small unit Tpaste (14 oz) Tpaste (8 oz) Pack-l (1) Cap (1) Pack-s (1) Cap (1) Both End products use the same Tpaste and the same Cap.

Product Information and Requirements Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 Demand/ Requirements Large unit Week 10 = 190 Week 11 = 120 Week 12 = 780 Small unit Week 9 = 250 Week 11 = 425 Week 12 = 200

MRP Table for the parent items (2) Demand/ Requirements Week 10 = 190 Week 11 = 120 Week 12 = 780 Large 6 7 8 9 10 11 12 13 GR 190 120 780 OH 330 210 NR 70 570 PR 400 PE Large From Tutorial 1 The production release for Large unit is as follows: Large 6 7 8 9 10 11 12 13 PE 400 570

MRP Table for the parent items (2) Demand/ Requirements Week 9 = 250 Week 11 = 425 Week 12 = 200 Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH NR PR PE Small unit The demand requirements are the GR

MRP Table for the parent items (2) Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 NR PR PE Current week = 6 Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 The initial OH from the table goes into the first week as OH The OH carries over until the first week with a GR

MRP Table for the parent items (2) Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 60 NR PR PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 NR = 0 as the OH > GR OH next period = PR + OH – GR = 0 + 310 – 250 = 60

MRP Table for the parent items (2) Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 60 NR 365 PR 500 PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 NR = GR – OH = 425 – 60 = 365 to determine the PR The minimum is 500 therefore PR = 500 PE = PR moved one week

MRP Table for the parent items (2) Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 60 135 NR 365 65 PR 500 PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 OH next period = PR + OH – GR = 500 + 60 – 425 = 135 NR = GR – OH = 65

MRP Table for the parent items (2) Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 60 135 435 NR 365 65 PR 500 PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 to determine the PR The minimum is 500 therefore PR = 500. PE = PR moved one week OH = PR + OH – GR = = 500 + 135 – 200 = 435

MRP Table for the parent items (2) Demand/ Requirements Week 9 = 250 Week 11 = 425 Week 12 = 200 Small 6 7 8 9 10 11 12 13 GR 250 425 200 OH 310 60 135 435 NR 365 65 PR 500 PE Small unit The production release for Small unit is as follows: Small 6 7 8 9 10 11 12 13 PE 500

The process is repeated MRP Tables must be completed for all components. At this time could do any of the four. Will do Pack-s Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 Pack-s (1)

MRP Table for the Pack-s Demand for Pack-s depends on its parent item (Small unit) So based on the PE (planned releases) of the parent item Relationship: 1 Pack-s per 1 Small unit parent Small 6 7 8 9 10 11 12 13 PE 500 Pack-s 6 7 8 9 10 11 12 13 GR 500 OH NR PR PE

MRP Table for the Pack-s Small 6 7 8 9 10 11 12 13 GR 500 OH NR PR PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 The initial OH from the table goes into the first week as OH OH carries over until the first week with a GR NR = GR – OH = 500 PR = NR as there is no minimum or lot size PE is the same as the PR offset by the lead time

MRP Table for the Pack-s Small 6 7 8 9 10 11 12 13 GR 500 OH NR PR PE Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000 OH next period = GR – PR – OH = 500 – 500 – 0 = 0 Rest is the same as in the previous week.

MRP Table for the Pack-s Small 6 7 8 9 10 11 12 13 GR 500 OH NR PR PE The completed MRP table for the Pack-s The production release for Pack-s is as follows: Pack-s 6 7 8 9 10 11 12 13 PE 500

MRP Table for the Pack-l 6 7 8 9 10 11 12 13 GR 400 570 OH 340 90 120 NR 60 480 PR 150 600 PE The completed MRP table for Pack-l From Tutorial 1 The production release for Pack-l is as follows: Pack-l 6 7 8 9 10 11 12 13 PE 150 600

MRP Table for Cap This is an item (component) that has multiple parents. Therefore it must be based on the production releases of all its “parents” simultaneously.

MRP Table for Cap Large 6 7 8 9 10 11 12 13 Small 6 7 8 9 10 11 12 13 PE 400 570 Small 6 7 8 9 10 11 12 13 PE 500 One Cap per Large One Cap per Small Cap 6 7 8 9 10 11 12 13 GR 400 500 1,070 OH NR PR PE

MRP Table for Cap Cap 6 7 8 9 10 11 12 13 GR 400 500 1,070 OH NR PR PE OH starts at 0. Given there is no lot size or minimum the PR = NR. PE = PR offset by one week Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000

MRP Table for Cap Cap 6 7 8 9 10 11 12 13 GR 400 500 1,070 OH NR PR PE The completed MRP table for the Cap The production release for Cap is as follows (with demand from the 2 end items): Cap 6 7 8 9 10 11 12 13 PE 400 500 1,070

MRP Table for Tpaste This is an item (component) that has multiple parents. Therefore it must be based on the production releases of all its “parents” simultaneously.

MRP Table for Tpaste This is in ounces Large 6 7 8 9 10 11 12 13 PE 400 570 14 ounces per Large unit 8 ounces per Small unit Small 6 7 8 9 10 11 12 13 PE 500 570 x 14 + 500 x 8 400 x 14 500 x 8 Tpaste 6 7 8 9 10 11 12 13 GR 5,600 4,000 11,980 OH NR PR PE This is in ounces

MRP Table for the Tpaste 6 7 8 9 10 11 12 13 GR 5,600 4,000 11,980 OH 970 NR 4,630 PR 6,000 PE OH starts at 970. PR is based on a LS = 3,000 Need two lots to satisfy the NR PR = 6,000 PE = PR offset by one week Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000

MRP Table for the Tpaste 6 7 8 9 10 11 12 13 GR 5,600 4,000 11,980 OH 970 1,370 NR 4,630 2,630 PR 6,000 3,000 PE OH next week OH + PR – GR = 1,370. PR is based on a LS = 3,000 Need 1 lot to satisfy the NR PR = 3,000 PE = PR offset by one week Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000

MRP Table for the Tpaste 6 7 8 9 10 11 12 13 GR 5,600 4,000 11,980 OH 970 1,370 370 390 NR 4,630 2,630 11,610 PR 6,000 3,000 12,000 PE OH next week (week 11) OH + PR – GR = 1,370 + 3,000 – 4,000 =370. PR is based on a LS = 3,000 Need 4 lots to satisfy the NR. PR = 12,000 PE = PR offset by one week OH next week (week 12) OH + PR – GR = 370 + 12,000 – 11,980 = 390. Item OH LT Lot Size or Min. Large unit 120 1 M = 400 Small unit 310 M = 500 Pack-l 340 2 LS = 150 Pack-s None Cap Tpaste 970 LS = 3,000

MRP Table for the Tpaste 6 7 8 9 10 11 12 13 GR 5,600 4,000 11,980 OH 970 1,370 370 390 NR 4,630 2,630 11,610 PR 6,000 3,000 12,000 PE The completed MRP table for Tpaste The production release for Tpaste is as follows (with demand from the 2 end items): : Tpaste 6 7 8 9 10 11 12 13 PE 6,000 3,000 12,000

Production Plan These are the release schedules of production as to meet the customer demand. PEs 6 7 8 9 10 11 12 13 Large 400 570 Small 500 Pack-l 150 600 Pack-s 500 Cap 400 570 Tpaste 6,000 3,000 12,000