The document discusses Material Requirements Planning (MRP). It begins by defining MRP from different perspectives and outlines the basic steps of MRP which include identifying requirements, running MRP to create suggestions, and firming the suggestions. The document also discusses important MRP inputs like the product structure file, master production schedule, and inventory master file. It provides an overview of the typical MRP system and process, which uses an MRP matrix to schedule production of all items.

1. 物料需求規劃
Material Requirement Planning (MRP)
覃崇耀
Chung Y. Ching
世新大學傳管系副教授

2. 大綱
有關MRP的參考書籍、期刊、網站
1.
不同觀點看MRP的定義
2.
MRP
MRP的演進
3.
MRP的邏輯
4.
MRP的實施
5.
MRP的檢討
6.

3. 有關MRP的參考書籍、網站、期
刊
Orlicky, J. A., Material Requirements
1.
Planning,New York: McGraw-Hill, 1975
Plossl, G. W., Orlicky’s Material
2.
Require-ments Planning,(2nd edition)
New York : McGraw-Hill, 1994
Browne, J., J. Harhen, and J. Shivnan,
3.
Production Management Systems:An
Integrated Perspective, New York :
McGraw-Hill, 1994
有關生管的教科書
4.

4. 有關MRP的參考書籍、網站、
期刊
http://www.google.com (browse: erp or mrp)
http://www.itbp.com/opsmanagement/iebm/material_requireme
nts.htm
http://www.vaihome.com/s2000mrp.htm
http://www.inventorysolutions.org/def_mrp.htm

5. 有關MRP的參考書籍、網站、
期刊
1. Production and Inventory Management Journal.
2. Journal of Operations Management.
3. International Journal of Production Research.
4. International Journal of Production Economic.
5. International Journal of Production Research.
6. Computer and IE
7. 等等.

6. 不同觀點看

MRP的定義

7. 生產是：
What is to be made?
1.
How many, and when are they needed?
2.
What resources are required to do this?
3.
Which are already available?
4.
Which others will be available in time?
5.
What more will be need?
6.

8. MRP的定義
生產管理系統的觀點

Part of the Production Management Systems

Focus on Manufacturing Planning


9. Forecasts Production planning Resource
requirements planning
Master production Rough cut capacity
Customer
schedule planning
orders
Material requirements Capacity requirements
planning planning
Production activity control
Purchasing
Dispatching Input/output control
Figure 1 The hierarchy of PMS

10. Part of the Production Management Systems (I)

Year Concept Tool Originator
科學管理原則 工作、時間研究
1910s F. W. Taylor
工業心理學 動作研究 Frank & Lillian Gilbreth
移動組裝線 動作排程圖 Henry Ford & H. Gantt
經濟批量 E.O.Q F. W. Harris
品質管制 抽樣、統計品管表 W. Shewhart, H. Roming
1930s
E. Mayo, L. H. Tippett
作業員工激勵 工作分析之作業抽樣
跨學門團隊解決複 線性規劃之單體法 OR group, George B.
1940s
（simplex method） Dantzig
雜系統問題
擴大發展作業研究 模擬、等候線理論、 Many researchers in
1950s-
決策理論、數學規 the United States and
之工具問題
1960s
劃、專案排程技術 Western Europe
PERT/CPM
現場排程、存貨管
電腦之廣泛運用
1970s IBM, J. Orlicky, O.
制、預測、專案管 Wight
理、MRP
服務業之量產
服務品質與生產力 McDonald’s restaurants

11. Part of the Production Management Systems (II)

Year Concept Tool Originator
製造策略典範 製造成為競爭武器
1980s Harvard faculty
JIT、TQC、工廠 Kanban, Poka-yokes, Ohno, Deming,
自動化 CIM, FMS, CAD/CAM
Bottleneck Analysis、 Eliyahu M.
OPT、TOC
同步製造 Goldratt
全面品管（TQM） Baldrige品質獎、
1990s NIST, ASQC, IOS,
ISO9000
品質功能展開、價值與同 M. Hammer&
步工程、持續改善典範 major consulting
企業再造
徹底改革典範 U.S. Government,
Netscape,
Internet, World Wide
電子化企業
Microsoft Co.
Web
供應鏈管理 SAP/R3, client/server SAP, Oracle
（SCM） software
電子商務
2000s Internet, World Wide Amazon, e-bay,
Web America Online,
Yahoo

12. MRP的定義
管理資訊系統的觀點

Part of the Computerized Integrated

Manufacturing Information Systems
Focus on Manufacturing Planning and Control


13. MRP的定義
生產計畫與管制的觀點

Computerized Planning and Control Systems

Focus on Manufacturing Information Flow


14. Master
Production
Schedule
Planning
MRP
System
Purchasing Scheduling
Scheduling Scheduling
Control
Scheduling Scheduling
Scheduling Scheduling

15. MRP的定義
存貨管理系統的觀點

Reorder point

Economic Ordering Quantity (EOQ)

Exposition and time-phased Inventory System


16. MRP的定義
產能管理系統的觀點

Infinite capacities

Push system

Equal weighted item priority


17. Independent Master
item demand production
schedule
Inventory MRP
Inventory Product
transactions system
Status structure
records record
Inventory
order action
Priority
planning
Priority
integrity
Planned-order
schedules
To capacity
requirements
Performance
planning system
control
Exception
reports

18. Figure. MPC Classification Schema
CPM/PERT
Number MRP
of subparts Just-in-time
Repetitive
Flow
Seconds Minutes Days Weeks Months
Examples: Oil, food, drugs, watches, TV, trucks, planes, houses, ships

19. Production Demand
Resource
Planning Management
Planning
Master
Production Front end
Scheduling
Detail Inventory
Routing Bills of
Material status
file material
Planning data
Timed-phased
Detail Requirement
Capacity (MRP) records
Planning
Material
and Capacity
Engine
Plans
Manufacturing
Planning and Control
System Shop-
Vendor
floor
Back end
System
System

20. Contributors to MRP
Joseph Orlicky (mrp)

 George Plossl (mrp)
 Oliver Wight (mrp II)
 American Production and Inventory
Control Society (APICS)

21. What is MRP?
不同觀點看MRP
 Computerized Inventory Control
 Production Planning System
 Management Information
System
 Manufacturing Control System

22. When to use MRP
Job Shop Production

 Complex Products
 Assemble-to-Order Environments
 Discrete and Dependent Demand
Items

23. What can MRP do?
Reduce Inventory Reduce Purchasing
 
Levels Cost
Reduce Component Improve Production
 
Shortages Schedules
Improve Shipping Reduce Manufacturing
 
Performance Cost
Improve Customer Reduce Lead Times
 
Service Less Scrap and

Improve Productivity Rework

Simplified and Higher Production
 
Accurate Scheduling Quality

24. What can MRP do?
Improve Reduce Overtime
 
Communication Improve Supply

Improve Plant Schedules

Efficiency Improve Calculation

Reduce Freight Cost of Material

Requirements
Reduction in Excess

Inventory Improve Competitive

Position

25. Three Basic Steps of
MRP
 IdentifyingRequirements
 Running MRP – Creating the
Suggestions
 Firming the Suggestions

26. Step 1: Identifying the
Requirements
Quantity on Hand

 Quantity on Open Purchase Order
 Quantity in/or Planned for
Manufacturing
 Quantity Committed to Existing
Orders
 Quantity Forecasted

27. Step 1: Important
Information
MRP is…..
Company Sensitive

 Location Sensitive
 Date Sensitive

28. Step 2: Running MRP –
Creating the
Suggestions
Critical Items

 Expedite Items
 Delay Items

29. Step 3: Firming the
Suggestions
 Manufacturing Orders
 Purchasing Orders
 Various Reports

30. Overview of the MRP
System
Product Master
Inventory
Structure Production
Master File
File Schedule
Material
Requirements
Planning
Purchase
Manufacturing Various
Orders
Orders Reports

31. MRP Inputs
 Product Structure File
 Master Production Schedule
 Inventory Master File

32. Product Structure File
 Bill of Materials

33. Master Production Schedule
Schedule of Finished Products

 Represents Production, not Demand
 Combination of Customer Orders and
Demand Forecasts
 What Needs to be Produced

34. Inventory Master
File
 On-Hand Quantities
 On-Order Quantities
 Lot Sizes
 Safety Stock
 Lead Time
 Past-Usage Figures

35. MRP Process
Schedules the Production of all items

using an MRP Matrix
MRP Matrix
Item: Low-Level Code:
PD 1 2345
Lot Size: Lead Time:
Gross Requirements
Scheduled Receipts
Projected on Hand
Net Requirements
Planned Order
Receipts
Planned Order
Releases

36. Terms Defined
Item – name or number for the item being

scheduled
Low-Level Code – the lowest level of the

item on the product structure file
Lot Size – order multiples of quantity

Lead Time – the time from when an order is

placed to when it is received
PD – Past Due Time Bucket, orders behind

schedule

37. Terms Defined
Gross Requirements – demand for an item

by time period
Scheduled Receipts – material already

ordered
Projected on Hand – expected ending

inventory
Net Requirements – number of items to be

provided and when
Planned Order Receipts – net requirements

adjusted for lot size
Planned Order Releases – planned order

receipts offset for lead times

38. Example of the MRP
Process
Item: A Low-Level Code: 1
PD 1 2 3 4 5
Lot Size: 25 Lead Time: 1
Gross Requirements 10 15 25 25 30
Scheduled Receipts 25
Projected on Hand 20
Net Requirements
Planned Order Receipts
Planned Order Releases

39. Example of the MRP
Process
Item: A Low-Level Code: 1
PD 1 2 3 4 5
Lot Size: 25 min Lead Time: 1
Gross Requirements 10 15 25 25 30
Scheduled Receipts 25
Projected on Hand 20 10 20 20 20 15
Net Requirements 5 5 10
Planned Order Receipts 25 25 25
Planned Order Releases 25 25 25 30 25

40. MRP Outputs
 Manufacturing Orders
 Purchasing Orders
 Various Reports

41. Hubbell Lighting Case
Manufactures Industrial Lighting

Products
Good-Quality Products

Poor at Meeting Due Dates

Work is Specialized for Each Customer

Job Shop Environment

Complex Products


42. Hubbell Lighting Case
After MRP Implementation
Before MRP
Implementation
97% of orders completed

Less than 75% of orders time
on

completed on time  2% of orders completed
with 1 to 2 days after due
date

43. Summary of MRP
MRP is a…..
 Computerized Inventory Control
 Production Planning System
that…..
 Schedules Component Items as Needed
which will…..
 Track Inventory and…..
 Help you in many other aspects of business