chapter 5 生產製造循環 (ii) 淡江大學資訊管理學系徐煥智整理編撰....

Chapter 5 生產製造循環 (II)

淡江大學資訊管理學系徐煥智整理編撰

物料需求計劃(Material Requirements Planning)

• 對衍生需求的優先次序規劃

對車子的需求

衍生出

對輪胎的需求


What to orderHow much to orderWhen to orderWhen to schedule delivery

Note: MRP 用來規劃所有資源的未來需求 .


MRP

MPS

BOM

InventoryRecords

工令

請購單


•Bill of Material Structure

1. 彙總式 (Summarized Parts List)

2. 多階式 (Multilevel Bill)

3. 單階式 (Single-Level Bill)

4. 規劃料表 (Planning Bill)


•彙總式 (Summarized Parts List)

料號名稱數量欄位

B 1

C 1

D 3

E 2

F 1

G 1

項目 A

E(1) F(1)

B(1)

D(1) E(1) G(1)

C(1) D(2)

A

Product Tree


•多階式 (Multilevel Bill)

F

J K (2)

G(2)

B(2) C

M (2) N

D

X

P

J K (2)

G

L M N(2) O

Y


•單階式 (Single-Level Bill)

B(2) C D

X

L M N(2) O

Y

F G(2)

B

M (2) N

D

P G

L

J K (2)

G


•規劃料表 (Planning Bill) - Used to simplify forecasting (MPS, MRP)

Common parts L egs Sides Tops

Table

Leg A40%

Leg B35%

Leg C25%

Side A55%

Side B30%

Side C15%

Top A45%

Top B30%

Top C25%

100%


用途表 (Where-Used Report)

•與 BOM 相關表格

溯源報表 (Pegging Report)

Where-used reports give the same information as a BOM, butthe where-used report gives the parents for a component whereas the BOM gives the components for a parent.

A pegging report is similar to where-used report. However, the pegging report shows only those parents for which there is an existing requirement.


•溯源報表 (Pegging Report)

WeekItemNumber

1 2 3 4 5

C 50 125 25 50 150

A 50 25 25 50 50

B 100 100

Pegged Requirements

Source of Requirements

C

C D

B

A


•MRP Process

Exploding andOffsetting

Gross and NetRequirements

Releasing Orders


•Exploding and Offsetting - Example

D(L T=1) E(L T=1)

B(L T=2) C(L T=1)

A (L T=1)

WeekPartNumber

1 2 3 4 5

A Planned Order ReceiptPlanned Order Release 50

50

B Planned Order ReceiptPlanned Order Release 50

50

C Planned Order ReceiptPlanned Order Release 50

50

D Planned Order ReceiptPlanned Order Release 50

50

E Planned Order ReceiptPlanned Order Release 50

50

Planned Order

(MPS)


•Gross and Net Requirement - ExampleWeekPart

Number

1 2 3 4 5

A Gross RequirementProjected Available 20Net RequirementPlanned Order ReceiptPlanned Order Release

20 20 20 20

30

5003030

B Gross RequirementProjected Available 10Net RequirementPlanned Order ReceiptPlanned Order Release

10 10

20

103002020

C Gross RequirementProjected AvailableNet RequirementPlanned Order ReceiptPlanned Order Release

0

30

3003030

D Gross RequirementProjected AvailableNet RequirementPlanned Order ReceiptPlanned Order Release

0

20

2002020

E Gross RequirementProjected AvailableNet RequirementPlanned Order ReceiptPlanned Order Release

0

20

2002020


•Released Order - Scheduled Receipt

The scheduled receipts row shows the quantities ordered and when theyare expected to be completed and available.

WeekPartNumber

1 2 3 4 5

D Gross RequirementScheduled ReceiptsProjected AvailableNet RequirementPlanned Order ReceiptPlanned Order Release

0

202000

E Gross RequirementScheduled ReceiptsProjected AvailableNet RequirementPlanned Order ReceiptPlanned Order Release

0

202000

Note: Net Requirement = Gross Requirement - Scheduled Receipts - Available Inventory


MRP 不安定性

• 高階項目的小改變造成低階項目的大改變。• MRP 系統做出的排程若經常改變將傷害 MRP的可信度。

• 變化的原因： MPS 變化、供應商遲交、品質問題、記錄錯誤、意外的異動。


Fundamental Wrong with MRP

MRP

Flawed Model

)f( numberpart timelead

Note: Lead times are not affected by the status of the plant

MRP II Hierarchy

DemandForecast

AggregatePlanning

ResourcePlanning

MPSRough-Cut

Capacity Planning

MRP

Job Pool

JobRelease

JobDispatching

Capacity RequirementPlanning

BOM

InventoryStatus

RoutingData

Long-RangePlanning

Intermediate-RangePlanning

Short-TermPlanning

CRP

Planned Order Releases

Open Orders

Routing DataCapacity and lead Time

for Process Centers

Shop Calendar

Work Center Load Report

產能需求規劃(Capacity Requirement Planning)


Part Name: Gear Shaft Part Number: SG123Drawing Number: D123X

Operation Work S/U Time Run Time/Piece No. Center (Standard Hours) (Standard Hours) Operation

10 12 1.50 0.2 Turn Shaft 20 14 0.50 0.25 Mill Slot 30 17 0.30 0.05 Drill Hole 40 03 0.45 0.10 Grind 50 Stores Inventory

Routing Data


WorkCenter

QueueTime

WaitTime

MoveTime

AvailableTime

Utilization Efficiency

12 4 1 1 24 100% 100%14 3 1 1 24 100% 100%17 5 1 1 24 100% 100%03 8 1 1 24 100% 100%

Work Center File


Ex: A work center has the following open orders and planned orders for week 20. Calculate the total standard time required (load) on this work center in week 20. Order 222 is already in progress, and there are 100 remaining to run.

OrderQuantity

SetupTime

RunTime

Released Orders

Planned Orders

222333

100150

01.5

0.20.2

444555

200300

32.5

0.250.15


Week 20 21 22 23 24 TotalReleased

Load51.5 45 30 30 25 181.5

PlannedLoad

100.5 120 100 90 100 510.5

Total Load 152 165 130 120 125 692Rated

Capacity140 140 140 140 140 700

Over/UnderCapacity

-12 -25 10 20 15 8

Work Center Load Report

結論

chapter 5 生產製造循環 (ii) 淡江大學資訊管理學系 徐煥智整理編撰....

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chapter 5 生產製造循環 (ii) 淡江大學資訊管理學系徐煥智整理編撰....