04 chap016 aquino chase
Post on 08-Apr-2018
223 Views
Preview:
TRANSCRIPT
-
8/7/2019 04 chap016 Aquino Chase
1/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
1
-
8/7/2019 04 chap016 Aquino Chase
2/28
The McGraw-Hill Companies, Inc., 2004
2
McGraw-Hill/Irwin
Chapter 16Materials
RequirementsPlanning
-
8/7/2019 04 chap016 Aquino Chase
3/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
3
Material Requirements Planning(MRP)
MRP Logic and Product StructureTrees
Time Fences
MRP Example MRP II and Lot Sizing
OBJECTIVES
-
8/7/2019 04 chap016 Aquino Chase
4/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
4
Material Requirements
Planning
Materials requirements planning (MRP)is a means for determining the numberof parts, components, and materials
needed to produce a product MRP provides time scheduling
information specifying when each ofthe materials, parts, and components
should be ordered or produced Dependent demand drives MRP
MRP is a software system
-
8/7/2019 04 chap016 Aquino Chase
5/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
5
Example of MRP Logic and
Product Structure Tree
(4)
E(1)D(2)
C(2)
F(2)D(3)
A
Product Structure Tree for Assembly A Lead Times
A 1 day
B 2 days
C 1 day
D 3 days
E 4 days
F 1 day
Total Unit Demand
Day 10 50 A
Day 8 20 B (Spares)
Day 6 15 D (Spares)
Given theproduct structure tree for A and the lead time anddemandinformation below, provide a materials requirements
plan that defines thenumberofunits ofeach component and
when theywill beneeded
-
8/7/2019 04 chap016 Aquino Chase
6/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
6
LT = 1 day
Day: 1 2 3 4 5 6 7 8 9 10
A Required 50
Order Placement 50
First, thenumberofunits ofA are scheduled
backwards to allowfor their lead time. So,in thematerials requirement plan below,we have to place
anorderfor 50 units ofA on the 9th day toreceive
themonday 10.
-
8/7/2019 04 chap016 Aquino Chase
7/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
7
Next,weneed to start scheduling the components that makeup
A. In the caseofcomponent B weneed 4 Bs foreach A.
Sinceweneed 50 As, that means 200 Bs. And again,we back
the scheduleup for thenecessary 2 days oflead time.
D a y : 1 2 3 4 5 6 7 8 9 1 0
A R e q u i re d 5 0
O rd e r P la c e m e n t 5 0
B R e q u i re d 2 0 2 0 0
O rd e r P la c e m e n t 2 0 2 0 0
B(4)
E(1)D(2)
C(2)
F(2)D(3)
A
SparesLT = 2
4x50=200
-
8/7/2019 04 chap016 Aquino Chase
8/28
Day: 1 2 3 4 5 6 7 8 9 10
A Required 50LT=1 Order Placement 50
B Required 20 200
LT=2 Order Placement 20 200
C Required 100
LT=1 Order Placement 100
D Required 55 400 300
LT=3 Order Placement 55 400 300
E Required 20 200
LT=4 Order Placement 20 200
F Required 200
LT=1 Order Placement 200
B(4)
E(1)D(2)
C(2)
F(2)D(3)
A
40 + 15 spares
Part D: Day 6
Finally,repeating the process for all components,we have the
final materials requirements plan:
The McGraw-Hill Companies, Inc., 2001
8
-
8/7/2019 04 chap016 Aquino Chase
9/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
9
Master Production Schedule (MPS)
Time-phased plan specifying how
manyand when the firm plans to build
each end item
Aggregate Plan
(Product Groups)
MPS
(Specific End Items)
-
8/7/2019 04 chap016 Aquino Chase
10/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
10
Types of Time Fences
Frozen No schedule changes allowed within
this window
Moderately Firm
Specific changes allowed withinproduct groups as long as parts areavailable
Flexible
Significant variation allowed as longas overall capacity requirementsremain at the same levels
-
8/7/2019 04 chap016 Aquino Chase
11/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
11
Example of Time Fences
8 15 26
Weeks
FrozenModerately
Firm Flexible
Firm Customer Orders
Forecast and availablecapacity
Capacity
Exhibit 15.5
-
8/7/2019 04 chap016 Aquino Chase
12/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
12
Material Requirements Planning System
Based on a master production schedule, amaterial requirements planning system:
Creates schedules identifying the specific
parts and materials required to produce
end items
Determines exact unit numbers needed
Determines the dates when orders for
those materials should be released, basedon lead times
-
8/7/2019 04 chap016 Aquino Chase
13/28
From Exhibit 15.6
13
The McGraw-Hill Companies, Inc., 2004
Firm orders
from known
customers
Forecasts
of demand
from random
customers
Aggregate
product
plan
Bill of
material
file
Engineering
design
changes
Inventory
record file
Inventory
transactions
Master production
Schedule (MPS)
Primary reportsSecondary reports
Planned order schedule for
inventory and production
control
Exception reports
Planning reports
Reports for performance
control
Material
planning
(MRP
computer
program)
-
8/7/2019 04 chap016 Aquino Chase
14/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
14
Bill of Materials (BOM) File
A Complete Product Description
Materials
Parts
Components Production sequence
ModularBOM
Subassemblies SuperBOM
Fractional options
-
8/7/2019 04 chap016 Aquino Chase
15/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
15
Inventory Records File
Each inventory item carried as a
separate file
Status according to time buckets
Pegging Identify each parent item that created
demand
-
8/7/2019 04 chap016 Aquino Chase
16/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
16
Primary MRP Reports
Planned orders to be released at a futuretime Order release notices to execute the
planned orders Changes in due dates of open orders
due to rescheduling Cancellations or suspensions of open
orders due to cancellation or suspensionof orders on the master production
schedule Inventory status data
-
8/7/2019 04 chap016 Aquino Chase
17/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
17
Secondary MRP Reports
Planning reports, for example,forecasting inventoryrequirements over a period of time
Performance reports used todetermine agreement betweenactual and programmed usageand costs
Exception reports used to pointout serious discrepancies, suchas late or overdue orders
-
8/7/2019 04 chap016 Aquino Chase
18/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
18
Additional MRP Scheduling Terminology
Gross Requirements
Scheduled receipts
Projected available balance
Net requirements
Planned order receipt
Planned order release
-
8/7/2019 04 chap016 Aquino Chase
19/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
19
MRP Example
A(2)B
(1)
D(5)C(2)
X
C(3)
Item On-Hand Lead Time (Weeks)
X 50 2
A 75 3
B 25 1
C 10 2
D 20 2
Requirements include 95 units (80 firm orders and 15 forecast) of X
in week 10
-
8/7/2019 04 chap016 Aquino Chase
20/28
-
8/7/2019 04 chap016 Aquino Chase
21/28
-
8/7/2019 04 chap016 Aquino Chase
22/28
-
8/7/2019 04 chap016 Aquino Chase
23/28
-
8/7/2019 04 chap016 Aquino Chase
24/28
-
8/7/2019 04 chap016 Aquino Chase
25/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
25
Closed Loop MRP
Production Planning
Master Production Scheduling
Material Requirements Planning
Capacity Requirements Planning
Realistic?No
Feedback
Execute:
Capacity Plans
Material Plans
Yes
Feedback
-
8/7/2019 04 chap016 Aquino Chase
26/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
26
Manufacturing Resource Planning
(MRP II)
Goal: Plan and monitor all resources of
a manufacturing firm (closed loop):
manufacturing marketing
finance
engineering
Simulate the manufacturing system
-
8/7/2019 04 chap016 Aquino Chase
27/28
McGraw-Hill/Irwin 2006 The McGraw-Hill Companies, Inc., All Rights Reserved.
27
Lot Sizing in MRP Programs
Lot-for-lot (L4L)
Economic order quantity (EOQ)
Least total cost (LTC) Least unit cost (LUC)
Which one to use?
The one that is least costly!
-
8/7/2019 04 chap016 Aquino Chase
28/28
The McGraw-Hill Companies, Inc., 2004
28
McGraw-Hill/Irwin
End of Chapter 16
top related