Transcript ch15R
Chapter 15
Resource Planning
Operations Management - 6 th Edition
Roberta Russell & Bernard W. Taylor, III
Copyright 2009 John Wiley & Sons, Inc.
Beni Asllani University of Tennessee at Chattanooga
Lecture Outline
Material Requirements Planning (MRP) Capacity Requirements Planning (CRP) Enterprise Resource Planning (ERP) Copyright 2009 John Wiley & Sons, Inc.
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Resource Planning for Manufacturing Copyright 2009 John Wiley & Sons, Inc.
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Material Requirements Planning (MRP)
Computerized inventory control and production planning system When to use MRP?
Dependent demand items Discrete demand items Complex products Job shop production Assemble-to-order environments Copyright 2009 John Wiley & Sons, Inc.
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Demand Characteristics
Independent demand Dependent demand 100 tables 400 – 300 – 200 – 100 – Continuous demand 1 2 3 Week 4 5
Copyright 2009 John Wiley & Sons, Inc.
100 x 1 = 100 tabletops 100 x 4 = 400 table legs 400 – 300 – 200 – 100 – Discrete demand M T W Th F M T W Th F
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Material Requirements Planning
Product structure file Master production schedule Material requirements planning Item master file Planned order releases Work orders
Copyright 2009 John Wiley & Sons, Inc.
Purchase orders Rescheduling notices
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MRP Inputs and Outputs
Inputs Master production schedule Product structure file Item master file Outputs Planned order releases Work orders Purchase orders Rescheduling notices Copyright 2009 John Wiley & Sons, Inc.
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Master Production Schedule
Drives MRP process with a schedule of finished products Quantities represent production not demand Quantities may consist of a combination of customer orders and demand forecasts Quantities represent what needs to be produced, not what can be produced Quantities represent end items that may or may not be finished products Copyright 2009 John Wiley & Sons, Inc.
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Master Production Schedule (cont.)
MPS ITEM Pencil Case Clipboard Lapboard Lapdesk
1
125 85 75 0
2
125 95 120 50 PERIOD
3
125 120 47 0
4
125 100 20 50
5
125 100 17 0 Copyright 2009 John Wiley & Sons, Inc.
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Product Structure
Clipboard Finished clipboard Pressboard (1) Top clip (1) Bottom clip (1) Pivot (1) Spring (1) Rivets (2)
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Product Structure Tree
Clipboard Level 0 Pressboard (1) Clip Ass’y (1) Rivets (2) Level 1 Top Clip (1) Bottom Clip (1) Pivot (1) Spring (1) Level 2
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Multilevel Indented BOM
LEVEL 0 - - - - 1 - - - - 2 - - - 2 - - - 2 - - - 2 - - 1 - - - 1 - - ITEM Clipboard Clip Assembly Top Clip Bottom Clip Pivot Spring Rivet Press Board UNIT OF MEASURE ea ea ea ea ea ea ea ea QUANTITY 1 1 1 1 1 1 2 1
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Item Master File
DESCRIPTION INVENTORY POLICY
Item Item no.
Item type Product/sales class Value class Buyer/planner Vendor/drawing Phantom code Unit price/cost Pegging LLC Pressboard 7341 Purch Comp B RSR 07142 N 1.25
Y 1 Lead time Annual demand Holding cost Ordering/setup cost Safety stock Reorder point EOQ Minimum order qty Maximum order qty Multiple order qty Policy code 1 5000 1 50 0 39 316 100 500 1 3 Copyright 2009 John Wiley & Sons, Inc.
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Item Master File (cont.)
PHYSICAL INVENTORY
On hand Location On order Allocated Cycle Last count Difference 150 W142 100 75 3 9/5 -2
USAGE/SALES
YTD usage/sales MTD usage/sales YTD receipts MTD receipts Last receipt Last issue 1100 75 1200 0 8/25 10/5 Cost acct.
Routing Engr
CODES
00754 00326 07142 Copyright 2009 John Wiley & Sons, Inc.
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MRP Processes
Exploding the bill of material Netting out inventory Lot sizing Time-phasing requirements Netting process of subtracting on hand quantities and scheduled receipts from gross requirements to produce net requirements Lot sizing determining the quantities in which items are usually made or purchased Copyright 2009 John Wiley & Sons, Inc.
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MRP Matrix
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MRP: Example
Master Production Schedule 1 Clipboard Lapdesk 85 0 2 95 60 3 120 0 4 100 60 5 100 0 Item Master File On hand On order (sch receipt) LLC Lot size Lead time CLIPBOARD 25 175 (Period 1) 0 L4L 1 Copyright 2009 John Wiley & Sons, Inc.
LAPDESK 20 0 0 Mult 50 1 PRESSBOARD 150 0 1 Min 100 1 15-17
MRP: Example (cont.)
Product Structure Record Clipboard Pressboard (1) Clip Ass’y (1) Rivets (2) Level 0 Level 1 Lapdesk Pressboard (2) Trim (3’) Copyright 2009 John Wiley & Sons, Inc.
Beanbag (1) Level 0 Glue (4 oz) Level 1 15-18
MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 25
1
85 175
2
PERIOD
3 4
95 120 100
5
100
Copyright 2009 John Wiley & Sons, Inc.
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 25
1
85 175 115 0
2
PERIOD
3 4
95 120 100
5
100 (25 + 175) = 200 units available (200 - 85) = 115 on hand at the end of Period 1
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 25
1
85 175 115 0
2
95 20 0 PERIOD
3 4
120 100
5
100 115 units available (115 - 85) = 20 on hand at the end of Period 2
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 25
1
85 175 115 0
2
95 PERIOD
3
120 20 0 0 100 100 100
4
100
5
100 20 units available (20 - 120) = -100 — 100 additional Clipboards are required Order must be placed in Period 2 to be received in Period 3
Copyright 2009 John Wiley & Sons, Inc.
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 25
1
85 175 115 0
2
95 PERIOD
3
120 20 0 100 0 100 100 100
4
100 0 100 100 100
5
100 0 100 100 Following the same logic Gross Requirements in Periods 4 and 5 develop Net Requirements, Planned Order Receipts, and Planned Order Releases
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MRP: Example (cont.)
ITEM: LAPDESK LOT SIZE: MULT 50 LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 20
1
0
2
PERIOD
3 4
60 0 60
5
0
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MRP: Example (cont.)
ITEM: LAPDESK LOT SIZE: MULT 50 LLC: 0 LT: 1 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases 20
1
0 20 0 50
2
PERIOD
3 4
60 0 60 10 40 50 10 0 50 50 50
5
0 0 Following the same logic, the Lapdesk MRP matrix is completed as shown
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 Planned Order Releases LT: 1 ITEM: LAPDESK LOT SIZE: MULT 50 LLC: 0 Planned Order Releases LT: 1 ITEM: PRESSBOARD LLC: 0 LOT SIZE: MIN 100 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases LT: 1 150
1 1
50
1 2
100 PERIOD
3
100
4
100
2 2
PERIOD
3
50 PERIOD
3 4 4 5 5 5
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 Planned Order Releases LT: 1 ITEM: LAPDESK LOT SIZE: MULT 50 LLC: 0 Planned Order Releases LT: 1 ITEM: PRESSBOARD LLC: 0 LOT SIZE: MIN 100 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases LT: 1 150
1 1
x1
50
x2
1
100
2
PERIOD
3 4
100
2
100 100 PERIOD
3
x1
4
50
x2
2
100 PERIOD
3
200
4
100
5
x1
5 5
0
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MRP: Example (cont.)
ITEM: CLIPBOARD LOT SIZE: L4L LLC: 0 Planned Order Releases LT: 1 ITEM: LAPDESK LOT SIZE: MULT 50 LLC: 0 Planned Order Releases LT: 1 ITEM: PRESSBOARD LLC: 0 LOT SIZE: MIN 100 Gross Requirements Scheduled Receipts Projected on Hand Net Requirements Planned Order Receipts Planned Order Releases LT: 1 150
1 1
50
1
100 50 100
2
100 PERIOD
3
100
4
100
2
PERIOD
3
50
4 2
100 PERIOD
3
200
4
100 50 50 100 150 0 150 150 100 0 100 100
5 5 5
0 0
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MRP: Example (cont.)
Planned Order Report ITEM Clipboard Lapdesk Pressboard
1
50 100
2
PERIOD
3 4
100 150 100 50 100 100
5
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CRP
Routing file MRP planned order releases Capacity requirements planning Load profile for each process
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Open orders file
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Calculating Capacity
Maximum capability to produce Rated Capacity Theoretical output that could be attained if a process were operating at full speed without interruption, exceptions, or downtime Effective Capacity Takes into account the efficiency with which a particular product or customer can be processed and the utilization of the scheduled hours or work Effective Daily Capacity = (no. of machines or workers) x (hours per shift) x (no. of shifts) x (utilization) x ( efficiency) Copyright 2009 John Wiley & Sons, Inc.
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Calculating Capacity (cont.)
Utilization Percent of available time spent working Efficiency How well a machine or worker performs compared to a standard output level Load Standard hours of work assigned to a facility Load Percent Ratio of load to capacity load Load Percent = x 100% capacity Copyright 2009 John Wiley & Sons, Inc.
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Load Profiles
graphical comparison of load versus capacity Leveling underloaded conditions: Acquire more work Pull work ahead that is scheduled for later time periods Reduce normal capacity Copyright 2009 John Wiley & Sons, Inc.
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Reducing Over-load Conditions
1. Eliminating unnecessary requirements 2. Rerouting jobs to alternative machines, workers, or work centers 3. Splitting lots between two or more machines 4. Increasing normal capacity 5. Subcontracting 6. Increasing efficiency of the operation 7. Pushing work back to later time periods 8. Revising master schedule Copyright 2009 John Wiley & Sons, Inc.
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Initial Load Profile
120 – 110 – 100 – 90 – 80 – 70 – 60 – 50 – 40 – 30 – 20 – 10 – 0 – 1 2 3 4 Time (weeks)
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5 6 Normal capacity
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Adjusted Load Profile
120 – 110 – 100 – 90 – 80 – 70 – 60 – 50 – 40 – 30 – 20 – 10 – 0 – Pull ahead Overtime Work an extra shift Push back Push back 1 2 3 4 Time (weeks) 5
Load leveling process of balancing underloads and overloads Copyright 2009 John Wiley & Sons, Inc.
6 Normal capacity
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Relaxing MRP Assumptions
Material is not always the most constraining resource Lead times can vary Not every transaction needs to be recorded Shop floor may require a more sophisticated scheduling system Scheduling in advance may not be appropriate for on-demand production. Copyright 2009 John Wiley & Sons, Inc.
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Enterprise Resource Planning (ERP)
Software that organizes and manages a company’s business processes by sharing information across functional areas integrating business processes facilitating customer interaction providing benefit to global companies Copyright 2009 John Wiley & Sons, Inc.
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Organizational Data Flows
Source:
Adapted from Joseph Brady, Ellen Monk, and Bret Wagner,
Concepts in Enterprise Resource Planning
(Boston: Course Technology, 2001), pp. 7 –12 Copyright 2009 John Wiley & Sons, Inc.
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ERP’s Central Database
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Selected Enterprise Software Vendors
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ERP Implementation
Analyze business processes Choose modules to implement Which processes have the biggest impact on customer relations?
Which process would benefit the most from integration?
Which processes should be standardized? Align level of sophistication Finalize delivery and access Link with external partners Copyright 2009 John Wiley & Sons, Inc.
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ERP and Software Systems
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