OPM case analysis
Resource Planning
Chapter 11
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11-‹#›
What is Resource Planning?
Resource Planning
A process that takes sales and operations plans; processes information in the way of time standards, routings, and other information on how services or products are produced; and then plans the input requirements
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2
Material Requirements Planning (MRP)
A computerized information developed specifically to help manufacturers manage dependent demand inventory and schedule replenishment orders
MRP Explosion
A process that converts the requirements of various final products into a material requirements plan that specifies the replenishment schedules of all the subassemblies, components, and raw materials needed to produce final products
Materials Requirements Planning
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3
Inventory
transactions
Inventory
records
Bills of
materials
Engineering
and process
designs
Other
sources
of demand
Authorized
master production
schedule
Material
requirements
plan
MRP
explosion
MRP Inputs
Figure 11.1
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4
Material Requirements Planning
Dependent demand
The demand for an item that occurs because the quantity required varies with the production plans for other items held in the firm’s inventory
Parent
An product that is manufactured from one or more components
Component
An item that goes through one or more operations to be transformed into or become part of one or more parents
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Material Requirements Planning
| | | | | | | | | |
1 5 10
Day
2,000 –
1,500 –
1,000 –
500 –
0
Bicycles
(a) Parent inventory
Reorder point
Order
1,000 on
day 3
Order
1,000 on
day 8
(b) Component demand
2,000 –
1,500 –
1,000 –
500 –
0
Rims
| | | | | | | | | |
1 5 10
Day
Figure 11.2
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6
Master Production Scheduling
Master Production Schedule (MPS)
A part of the material requirements plan that details how many end items will be produced within specified periods of time
In a Master Production Schedule:
Sums of quantities must equal sales and operations plan.
Production quantities must be allocated efficiently over time.
Capacity limitations and bottlenecks may determine the timing and size of MPS quantities.
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Master Production Scheduling
| April | May | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Ladder-back chair | ||||||||
| Kitchen chair | ||||||||
| Desk chair | ||||||||
| Aggregate production plans for chair family |
150
150
120
120
200
200
200
200
670
670
Figure 11.3
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No
Material requirements planning
Yes
Authorized master production schedule
Master Production Scheduling
Are resources available?
Prospective master production schedule
Authorized
production
plan
Figure 11.4
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9
Master Production Scheduling
Step 1: Calculate projected on-hand inventories
=
+
–
Projected on-hand inventory at end of this week
On-hand inventory at end of last week
MPS quantity due at start of this week
Projected requirements this week
where:
Projected requirements = Max(Forecast, Customer Orders Booked)
=
Inventory
+
55 chairs currently in stock
–
MPS quantity (0 for week 1)
38 chairs already promised for delivery in week 1
= 17 chairs
Developing a Master Production Schedule
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Item: Ladder-back chair
Quantity on Hand:
Forecast
Customer orders (booked)
Projected on-hand inventory
MPS quantity
MPS start
April
1
2
Master Production Scheduling
55
30
30
38
27
17
–13
0
0
Explanation:
Forecast is less than booked orders in week 1; projected on-hand inventory balance = 55 + 0 – 38 = 17.
Explanation:
Forecast exceeds booked orders in week 2; projected on-hand inventory balance = 17 + 0 – 30 = –13. The shortage signals a need to schedule an MPS quantity for completion in week 2.
Figure 11.6
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Master Production Scheduling
The goal is to maintain a nonnegative projected on-hand inventory balance
As shortages in inventory are detected, MPS quantities should be scheduled to cover them
Step 2: Determine the timing and size of MPS quantities
=
Inventory
17 chairs in inventory at the end of week 1
+
MPS quantity of 150 chairs
–
Forecast of 30 chairs
= 137 chairs
Developing a Master Production Schedule
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Item: Ladder-back chair
Order Policy: 150 units
Lead Time: 1 week
1
2
3
4
5
6
7
8
April
Forecast
Customer orders booked
Projected on-hand inventory
MPS quantity
MPS start
Quantity on Hand:
30
38
30
27
30
24
30
8
0
35
0
35
0
0
35
35
55
May
17
137
107
77
42
7
122
87
0
150
0
0
0
0
150
0
150
0
0
0
0
150
0
0
Master Production Schedule (MPS)
Explanation:
On-hand inventory balance = 17 + 150 – 30 = 137. The MPS quantity is needed to avoid a shortage of 30 – 17 = 13 chairs in week 2.
Explanation:
The time needed to assemble 150 chairs is 1 week. The assembly department must start assembling chairs in week 1 to have them ready by week 2.
Figure 11.7
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13
Master Production Scheduling
Available-to-promise (ATP) inventory
The quantity of end items that marketing can promise to deliver on specific dates
It is the difference between the customer orders already booked and the quantity that operations is planning to produce
Freezing the MPS
Disallow changes to the near-term portion of the MPS
Reconciling the MPS with Sales and Operations Plans
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Item: Ladder-back chair
Order Policy: 150 units
Lead Time: 1 week
1
2
3
4
5
6
7
8
April
Forecast
Customer orders booked
Projected on-hand inventory
MPS quantity
MPS start
Quantity on Hand:
30
38
30
27
30
24
30
8
0
35
0
35
0
0
35
35
55
May
17
137
107
77
42
7
122
87
0
150
0
0
0
0
150
0
150
0
0
0
0
150
0
0
Available-to-promise (ATP) inventory
17
91
150
Master Production Schedule (MPS)
Explanation:
The total of customer orders booked until the next MPS receipt is 38 units. The ATP = 55 (on-hand) + 0 (MPS quantity) – 38 = 17.
Explanation:
The total of customer orders booked until the next MPS receipt is 27 + 24 + 8 = 59 units. The ATP = 150 (MPS quantity) – 59 = 91 units..
Figure 11.8
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Application 11.1
Determine the MPS for Product A that has a 50-unit policy and 55 units on hand.
The demand forecast and booked orders are shown in the partially completed plan.
The lead time is one week.
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Application 11.1
| Item: Product A | Order Policy: 50 units | |||||||||
| Lead Time: 1 week | ||||||||||
| Quantity on Hand 55 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Forecast | 20 | 10 | 40 | 10 | 0 | 0 | 30 | 20 | 40 | 20 |
| Customer orders (booked) | 30 | 20 | 5 | 8 | 0 | 2 | 0 | 0 | 0 | 0 |
| Projected on-hand inventory | ||||||||||
| MPS quantity | ||||||||||
| MPS start | ||||||||||
| Available-to-promise (ATP) inventory |
| 25 | 5 |
| 50 | |
| 15 | 5 | 5 | 3 | 23 | 3 | 13 | 43 |
| 50 | 50 | 50 | 50 | ||||
| 50 | 50 | 50 | |||||
5
35
50
50
50
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Bill of Materials
A record of all the components of an item, the parent-component relationships, and the usage quantities derived from engineering and process designs
End items
Intermediate items
Subassemblies
Purchased items
Part commonality (sometimes called standardization of parts or modularity)
MRP Explosion
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Seat cushion
Seat-frame boards
Front legs
A
Ladder-back chair
Back legs
Leg supports
Back slats
MRP Explosion
Bill of Materials for a Ladder-Back Chair
Figure 11.10
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J (4)
Seat-frame boards
MRP Explosion
G (4)
Back slats
F (2)
Back legs
I (1)
Seat cushion
H (1)
Seat frame
C (1)
Seat
subassembly
D (2)
Front
legs
B (1)
Ladder-back
subassembly
E (4)
Leg
supports
A
Ladder-back
chair
Figure 11.10
Bill of Materials for a Ladder-Back Chair
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MRP Explosion
Inventory record
A record that shows an item’s lot-size policy, lead time, and various time-phased data.
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MRP Explosion
The time-phase information contained in the inventory record consists of:
Gross requirements
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
=
+
–
Projected on-hand inventory balance at end of week t
Inventory on hand at end of week t–1
Scheduled or planned receipts in week t
Gross requirements in week t
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MRP Explosion
The on-hand inventory calculations for each week in the following slide are as follows
Week 1: 37 + 230 – 150 = 117
Weeks 2 and 3: 117 + 0 – 0 = 117
Week 4: 117 + 0 – 120 = –3
Week 5: –3 + 0 – 0 = –3
Week 6: –3 + 0 – 150 = –153
Week 7: –153 + 0 – 120 = –273
Week 8: –273 + 0 – 0 = –273
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MRP Explosion
| Item: C Description: Seat subassembly | Lot Size: 230 units Lead Time: 2 weeks | |||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Gross requirements | 0 | 0 | 0 | 0 | ||||
| Scheduled receipts | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Projected on-hand inventory | 117 | 117 | –3 | –3 | –153 | –273 | –273 | |
| Planned receipts | ||||||||
| Planned order releases |
Explanation:
Gross requirements are the total demand for the two chairs. Projected on-hand inventory in week 1 is 37 + 230 – 150 = 117 units.
37
120
120
150
150
117
230
Figure 11.11
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MRP Explosion
| Item: C Description: Seat subassembly | Lot Size: 230 units Lead Time: 2 weeks | |||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Gross requirements | 150 | 0 | 0 | |||||
| Scheduled receipts | 230 | 0 | 0 | |||||
| Projected on-hand inventory | 117 | 117 | 117 | |||||
| Planned receipts | ||||||||
| Planned order releases |
37
Without a planned receipt in week 4, a shortage of 3 units will occur: 117 + 0 + 0 – 120 = –3 units. Adding the planned receipt brings the balance to 117 + 0 + 230 – 120 = 227 units.
The first planned receipt lasts until week 7, when projected inventory would drop to 77 + 0 + 0 – 120 = –43 units. Adding the second planned receipt brings the balance to 77 + 0 + 230 – 120 = 187 units.
120
0
227
230
230
230
230
187
120
0
77
| 0 | 150 |
| 0 | 0 |
| 227 |
| 0 |
| 0 |
| 187 |
Figure 11.12
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Planning lead time
An estimate of the time between placing an order and receiving the item in inventory.
Planning lead time consists of estimates for:
Setup time
Processing time
Materials handling time between operations
Waiting time
Planning Factors
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Lot-sizing rules
Fixed order quantity (FQO) rule maintains the same order quantity each time an order is issued
Could be determined by quantity discounts, truckload capacity, minimum purchases, or EOQ
Planning Factors
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Lot-sizing rules
Periodic order quantity (POQ) rule allows a different order quantity for each order issued but issues the order for predetermined time intervals
Planning Factors
=
–
POQ lot size to arrive in week t
Total gross requirements for P week, including week t
Projected on-hand inventory balance at end of week t–1
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Planning Factors
=
–
(POQ lot size)
Gross requirements for weeks 4, 5, and 6
Inventory at end of week 3
Using P = 3:
(POQ lot size) = (120 + 0 + 150) – 117 = 153 units
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29
Planning Factors
Figure 11.13
Using POQ Rule
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Planning Factors
=
–
L4L lot size to arrive in week t
Gross requirements for week t
Projected on-hand inventory balance at end of week t – 1
=
–
(L4L lot size)
Gross requirements in week 4
Inventory balance at end of week 3
(L4L lot size) = 120 – 117 = 3 units
Lot-sizing rules
Lot-for-lot (L4L) rule under which the lot size ordered covers the gross requirements of a single week
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Planning Factors
Figure 11.14
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32
Application 11.2
| Item: H10-A Description: Chair seat assembly | Lot Size: FOQ = 80 units Lead Time: 4 weeks | |||||||||
| Week | ||||||||||
| 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | |
| Gross requirements | 60 | 35 | 45 | 60 | ||||||
| Scheduled receipts | 80 | |||||||||
| Projected on-hand inventory | ||||||||||
| Planned receipts | ||||||||||
| Planned order releases |
20
| 20 | 40 | 40 | 40 | 40 | 5 | 5 |
Item H10-A is a produced item (not purchased) with an order quantity of 80 units. Complete the rest of its MRP record using the fixed order quantity (FOQ) rule
80
80
40
40
80
80
60
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Application 11.3
Now complete the H10-A record using a POQ rule. The P should give an average lot size of 80 units.
Assume the average weekly requirements are 20 units.
P = = 4 weeks
80
20
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Application 11.3
| Item: H10-A Description: Chair seat assembly | Lot Size: POQ = 4 Lead Time: 4 weeks | |||||||||
| Week | ||||||||||
| 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | |
| Gross requirements | 60 | 35 | 45 | 60 | ||||||
| Scheduled receipts | 80 | |||||||||
| Projected on-hand inventory | ||||||||||
| Planned receipts | ||||||||||
| Planned order releases |
20
| 20 | 40 | 40 | 40 | 40 | 5 | 5 |
100
100
60
60
0
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Application 11.4
Revise the H10-A record using the lot-for-lot (L4L) Rule. (Complete the highlighted section)
| Item: H10-A Description: Chair seat assembly | Lot Size: L4L Lead Time: 4 weeks | |||||||||
| Week | ||||||||||
| 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | |
| Gross requirements | 60 | 35 | 45 | 60 | ||||||
| Scheduled receipts | 80 | |||||||||
| Projected on-hand inventory | ||||||||||
| Planned receipts | ||||||||||
| Planned order releases |
| 20 | 40 | 40 | 40 | 40 | 5 | 5 |
20
40
40
0
0
60
60
0
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Comparing lot-sizing rules
Planning Factors
FOQ:
= 181 units
227 + 227 + 77 + 187 + 187
5
POQ:
= 60 units
150 + 150 + 0 + 0 + 0
5
L4L:
= 0 units
0 + 0 + 0 + 0 + 0
5
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37
Lot sizes affect inventory, setup, and ordering costs
The FOQ rule generates a high level of average inventory because it creates inventory remnants.
The POQ rule reduces the amount of average on-hand inventory because it does a better job of matching order quantity to requirements.
The L4L rule minimizes inventory investment, but it also maximizes the number of orders placed.
Planning Factors
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Planning Factors
Safety stock for dependent demand items with lumpy demand (gross requirements) is helpful only when future gross requirements, the timing or size of scheduled receipts, and the amount of scrap that will be produced are uncertain.
Used for end items and purchased items to protect against fluctuating customer orders and unreliable suppliers of components but avoid using it as much as possible for intermediate items.
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Planning Factors
Safety Stock
Figure 11.15
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Manufacturing resources plan
Performance reports
Outputs from MRP
Material requirements plan
Action notices
Releasing new orders
Adjusting due dates
Priority reports
Dispatch lists
Supplier schedules
Capacity reports
Capacity requirements planning
Finite capacity scheduling
Input-output control
Cost and price data
MRP explosion
Routings and time standards
Figure 11.16
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41
Outputs from MRP
Material Requirements
An item’s gross requirements are derived from three sources:
The MPS for immediate parents that are end items
The planned order releases for immediate parents below the MPS level
Any other requirements not originating in the MPS, such as the demand for replacement parts
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Outputs from MRP
J(4)
Seat-frame boards
C(1)
Seat subassembly
H(1)
Seat frame
I(1)
Seat cushion
BOM for the Seat Subassembly
Figure 11.17
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43
Item: Seat subassembly
Lot size: 230 units
Lead
time: 2 weeks
Gross requirements
150
1
230
117
2
3
120
4
5
150
6
120
7
8
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
37
Week
117
117
0
0
0
0
0
0
0
0
0
0
0
227
227
77
187
187
230
230
230
230
Outputs from MRP
Figure 11.18
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44
The series starts with the MRP record for the end item.
Item: Seat frames
Lot size: 300 units
Lead
time: 1 week
Gross requirements
1
0
2
3
4
5
6
7
8
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
40
Week
0
0
0
300
0
0
0
Item: Seat cushion
Lot size: L4L
Lead
time: 1 week
Gross requirements
1
0
2
3
4
5
6
7
8
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
0
Week
0
0
0
0
0
0
0
Item: Seat subassembly
Lot size: 230 units
Lead
time: 2 weeks
Gross requirements
150
1
2
3
120
4
5
150
6
120
7
8
Planned receipts
Planned order releases
Week
0
0
0
0
230
230
230
230
Usage quantity: 1
Usage quantity: 1
0
230
0
230
0
230
0
0
230
0
Outputs from MRP
Figure 11.18
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45
These are the two records for level one items.
Item: Seat subassembly
Lot size: 230 units
Lead
time: 2 weeks
Gross requirements
150
1
2
3
120
4
5
150
6
120
7
8
Planned receipts
Planned order releases
Week
0
0
0
0
230
230
230
230
Item: Seat frames
Lot size: 300 units
Lead
time: 1 week
Gross requirements
1
0
2
3
4
5
6
7
8
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
40
Week
0
0
0
300
0
0
0
Item: Seat cushion
Lot size: L4L
Lead
time: 1 week
Gross requirements
1
0
2
3
4
5
6
7
8
Scheduled receipts
Projected on-hand inventory
Planned receipts
Planned order releases
0
Week
0
0
0
0
0
0
0
0
230
0
230
0
230
0
0
230
0
0
0
0
40
110
110
110
180
180
180
180
300
300
0
0
0
0
0
0
0
0
0
0
0
230
230
230
230
Figure 11.18
Outputs from MRP
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46
These are the two records for level one items.
Item: Seat frames
Lot size: 300 units
Lead
time: 1 week
Gross requirements
1
2
3
4
5
6
7
8
Planned receipts
Planned order releases
Week
300
300
Item: Seat cushion
Lot size: L4L
Lead
time: 1 week
Gross requirements
1
2
3
4
5
6
7
8
Planned receipts
Planned order releases
Week
230
230
230
230
0
0
0
0
230
230
0
0
0
0
0
0
230
230
0
0
Gross requirements
1
0
2
3
4
5
6
7
8
Scheduled receipts
Planned receipts
Planned order releases
200
Week
0
0
0
0
0
0
0
Projected on-hand inventory
Item: Seat-frame boards
Lot size: 1500 units
Lead
time: 1 week
Outputs from MRP
Usage quantity: 4
1200
200
200
200
500
500
500
500
500
1500
1500
Figure 11.18
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47
Once again, these are reduced and shortened for clarity.
This slide advances automatically.
Application 11.5
A firm makes a product (Item A) from three components (intermediate Items B and D, and purchased item C).
The latest MPS for product A calls for completion of a 250-unit order in week 8, and its lead time is 2 weeks.
The master schedule and bill of material for Product A are on the following slides:
| Item: End Item A | Lead Time: 2 wks | |||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| MPS quantity | 250 | |||||||
| MPS start | 250 |
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C(2)
C(2)
B(1)
Application 11.5
Develop a material requirements plan for items B, C, and D, given the following inventory data.
B(1)
C(1)
D(2)
A
| Data Category | Item | ||
| B | C | D | |
| Lot-sizing rule | POQ (P = 5) | FOQ = 1000 | L4L |
| Lead time | 2 weeks | 1 week | 3 weeks |
| Scheduled receipts | None | 1000 (week 1) | None |
| Beginning inventory | 0 | 800 | 0 |
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11-‹#›
Application 11.5
An item’s gross requirements cannot be derived until all of its immediate parents are processed.
Thus we must begin with Item D. Its only immediate parent is item A, and its planned “production plan” is shown by the MPS start row.
| Item: D Lot Size: L4L Description: Lead Time: 3 weeks | ||||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Gross requirements | ||||||||
| Scheduled receipts | ||||||||
| Projected on-hand inventory 0 | ||||||||
| Planned receipts | ||||||||
| Planned order releases |
0
0
0
500
0
0
0
500
500
0
0
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11-‹#›
Application 11.5
We can do item B next, because the planned “production quantities” for its two immediate parents (A and D) are known.
Item C cannot be done yet, because one of its parents is item B, and its PORs are still unknown.
| Item: B Lot Size: POQ = 5 Description: Lead Time: 2 weeks | ||||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Gross requirements | ||||||||
| Scheduled receipts | ||||||||
| Projected on-hand inventory 0 | ||||||||
| Planned receipts | ||||||||
| Planned order releases |
500
250
0
0
250
750
250
750
250
0
0
0
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Application 11.5
Finally we can do Item C, because we now know the planned “production quantities” of both of its immediate parents (A and B).
| Item: C Lot Size: 1000 Description: Lead Time: 1 week | ||||||||
| Week | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Gross requirements | ||||||||
| Scheduled receipts | 1000 | |||||||
| Projected on-hand inventory 800 | ||||||||
| Planned receipts | ||||||||
| Planned order releases |
1500
250
300
300
300
300
300
50
50
50
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Outputs from MRP
Action notices
A computer-generated memo alerting planners about releasing new orders and adjusting the due dates of scheduled receipts.
Resource Requirement Reports
Theory of constraints principles
Capacity requirements planning (CRP)
Performance Reports
Manufacturing resource planning (MRP II)
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MRP and the Environment
Consumer and government concern about the deterioration of the natural environment has driven manufacturers to reengineer their processes to become more environmentally friendly.
Companies can modify their MRP systems to help track these waste and plans for their disposal.
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MRP, Core Processes, and Supply Chain Linkages
The MRP system interacts with the four core processes of an organization
Supplier relationship process
New service/product development process
Order fulfillment process
Customer relationship process
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MRP, Core Processes, and Supply Chain Linkages
External Suppliers
External Customers
Supplier
Relationship
Process
MPS
Order
Fulfillment
Process
MRP
Customer
Relationship
Process
New Service/Product Development Process
Bill of Materials
Supplier
Orders
Customer
Orders
Order
Promises
And
Due Dates
Supplier Schedules
(Planned Order Releases)
Figure 11.19
Adjustments to due dates of scheduled releases
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Enterprise Resource Planning
Enterprise process
A companywide process that cuts across functional areas, business units, geographic regions, product lines, suppliers, and customers
Enterprise resource planning (ERP) systems
Large, integrated information systems that support many enterprise processes and data storage needs
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Back-Office Processes Front-Office Processes
Human
Resources
Benefits
Payroll
Data Analysis
Product costing
Job costs
Sales and Marketing
Sales orders
Pricing system
Customer Service
Field service
Quality
Supply-Chain
Management
Forecasting
Purchasing
Distribution
Accounting and Finance
Accounts payable and receivable
General ledgers
Asset management
Manufacturing
Material requirements planning
Scheduling
ERP System
Enterprise Resource Planning
Figure 11.20
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58
2
Resource Planning for Service Providers
Dependent demand for services
Restaurants
Airlines
Hospitals
Hotels
Bill of Resources (BOR)
A record of a service firm’s parent-component relationships and all of the materials, equipment time, staff, and other resources associated with them, including usage quantities.
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Bill of Resources
Consider a regional hospital that among many other procedures performs aneurysm treatments. The BOR (Figure 11.21) for treatment has 7 levels.
The hospital is interested in understanding how much of each critical resource of nurses, beds and lab tests will be needed if the projected patient departures from the aneurysm treatment process over the next 15 days are as shown in Table 11.1
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Level 1
Discharge
Level 2
Intermediate care
Level 3
Postoperative care
(Step down)
Level 4
Postoperative care
(Intensive)
Level 7
Preoperative care
(Testing)
Level 5
Surgery
Bill of Resources
Nurse
(6 hr)
MD
(1 hr)
Therapy
(1 hr)
Bed
(24 hr)
Lab
(3 tests)
Kitchen
(1 meal)
Pharmacy
(10
medicines)
Level 6
Preoperative care
(Angiogram)
Level 6
Preoperative care
(Angiogram
Figure 11.21
Cumulative lead time, or the patient stay time at the hospital, across all seven levels for the entire duration of the aneurysm treatment is 10 days.
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Bill of Resources
| Day of the Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| Aneurysm Patient | 1 | 2 | 1 | 3 | 2 | 3 | 0 | 1 | 2 | 1 | 2 | 2 | 2 | 2 | 2 |
Table 11.1
The first 10 days of the projected departures represent actual patients who have started the process while the last 5 days are forecasts based on historical records.
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Bill of Resources
| Resources Required for Each Aneurysm Patient | Nurse Hours Required Per Day Per Patient | Beds Required Per Day Per Patient | Lab Tests Required Per Day Per Patient |
| Level 1 | 0 | 0 | 0 |
| Level 2 | 6 | 0 | 0 |
| Level 3 | 16 | 1 | 4 |
| Level 4 | 12 | 1 | 6 |
| Level 5 | 22 | 1 | 2 |
| Level 6 | 6 | 1 | 3 |
| Level 7 | 1 | 0 | 0 |
Use the information above to calculate the daily resource requirements for treating aneurysm patients (similar to the gross requirements in a MRP record). Begin by calculating the number of patients that will be at each level (or stage) of treatment each day.
Table 11.2
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Bill of Resources
Figure 11.22
As shown below, the aneurysm patient departures become the Master Schedule for Level 1 and these departures drive the need for resources at each level of the process.
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Bill of Resources
Once we know how many patients will need each level of treatment on each day, we can multiply this demand by the amount of each resource required to treat them.
Example:
Total Number of Lab Tests Projected for Day 5
= [0(2) + 0(3) + 4(3) + 6(3) + 2(2) + 3(2) + 0(2)]
= 40
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Bill of Resources
| Day of the Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| Nursing Hours Required | 179 | 198 | 170 | 170 | 160 | 170 | 190 | 184 | 150 | 132 | 108 | 76 | 44 | 12 | 0 |
| Beds required | 12 | 12 | 11 | 11 | 10 | 12 | 13 | 11 | 10 | 8 | 6 | 4 | 2 | 0 | 0 |
| Lab Tests Required | 50 | 45 | 46 | 44 | 40 | 50 | 54 | 48 | 48 | 36 | 24 | 16 | 8 | 0 | 0 |
Table 11.3
The above table shows how much of each critical resource is required in total to treat aneurysm patients for the 15-day master schedule.
This table shows the resources needed from Day 1 to Day 15 for the current schedule.
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Solved Problem 1
Refer to the bill of materials for product A shown below.
If there is no existing inventory and no scheduled receipts, how many units of items G, E, and D must be purchased to produce 5 units of end item A?
LT = 2
LT = 3
B (3)
C (1)
G (1)
LT = 3
LT = 3
D (1)
LT = 3
D (1)
LT = 6
E (2)
LT = 1
F (1)
LT = 1
A
Figure 11.23
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67
Solved Problem 1
Five units of item G, 30 units of item E, and 20 units of item D must be purchased to make 5 units of A.
The usage quantities indicate that 2 units of E are needed to make 1 unit of B and that 3 units of B are needed to make 1 unit of A; therefore, 5 units of A require 30 units of E (2 3 5 = 30).
One unit of D is consumed to make 1 unit of B, and 3 units of B per unit of A result in 15 units of D (1 3 5 = 15)
One unit of D in each unit of C and 1 unit of C per unit of A result in another 5 units of D (1 1 5 = 5).
The total requirements to make 5 units of A are 20 units of D(15 + 5).
The calculation of requirements for G is simply 1 1 1 5 = 5 units.
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68
Solved Problem 2
The order policy is to produce end item A in lots of 50 units.
Complete the projected on-hand inventory and MPS quantity rows.
Complete the MPS start row by offsetting the MPS quantities for the final assembly lead time.
Compute the available-to-promise inventory for item A.
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Solved Problem 2
Assess the following customer requests for new orders.
Assume that these orders arrive consecutively and their affect on ATP is cumulative.
Which of these orders can be satisfied without altering the MPS Start quantities?
Customer A requests 30 units in week 1
Customer B requests 30 units in week 4
Customer C requests 10 units in week 3
Customer D requests 50 units in week 5
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Solved Problem 2
| Item: A | Order Policy: 50 units Lead Time: 1 week | |||||||||
| Week | ||||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Forecast | 20 | 10 | 40 | 10 | 0 | 0 | 30 | 20 | 40 | 20 |
| Customer orders (booked) | 30 | 20 | 5 | 8 | 0 | 2 | 0 | 0 | 0 | 0 |
| Projected on-hand inventory | 25 | |||||||||
| MPS quantity | 50 | |||||||||
| MPS start | ||||||||||
| Available-to-promise (ATP) inventory |
Quantity on Hand 5
Figure 11.24
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Solved Problem 2
The projected on-hand inventory for the second week is
=
+
–
Projected on-hand inventory at end of week 2
On-hand inventory in week 1
MPS quantity due in week 2
Requirements in week 2
= 25 + 0 – 20 = 5 units
where requirements are the larger of the forecast or actual customer orders booked for shipment during this period. No MPS quantity is required.
Without an MPS quantity in the third period, a shortage of item A will occur: 5 + 0 – 40 = –35.
Therefore, an MPS quantity equal to the lot size of 50 must be scheduled for completion in the third period. Then the projected on-hand inventory for the third week will be 5 + 50 – 40 = 15.
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Solved Problem 2
The MPS start row is completed by simply shifting a copy of the MPS quantity row to the left by one column to account for the 1-week final assembly lead time. Also shown are the available-to-promise quantities. In week 1, the ATP is
=
+
–
Available-to- promise in week 1
On-hand quantity in week 1
MPS quantity in week 1
Orders booked up to week 3 when the next MPS arrives
= 5 + 50 – (30 + 20) = 5 units
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Solved Problem 2
The ATP for the MPS quantity in week 3 is
=
–
Available-to- promise in week 3
MPS quantity in week 3
Orders booked up to week 7 when the next MPS arrives
= 50 – (5 + 8 + 0 + 2) = 35 units
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Solved Problem 2
Figure 11.25
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A
B (1)
C (2)
D (1)
LT = 2
LT = 1
LT = 2
LT = 3
Solved Problem 3
The MPS start quantities for product A calls for the assembly department to begin final assembly according to the following schedule:
100 units in week 2; 200 units in week 4
120 units in week 6; 180 units in week 7
60 units in week 8.
Develop a material requirements plan for the next 8 weeks for items B, C, and D.
Figure 11.26
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76
Solved Problem 3
| INVENTORY RECORD DATA | |||
| Item | |||
| Data Category | B | C | D |
| Lot-sizing rule | POQ (P =3) | L4L | FOQ = 500 units |
| Lead time | 1 week | 2 weeks | 3 weeks |
| Scheduled receipts | None | 200 (week 1) | None |
| Beginning (on-hand) inventory | 20 | 0 | 425 |
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77
Solved Problem 3
| Item: B | Lot Size: POQ (P = 3) Lead Time: 1 week | |||||||||
| Week | ||||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Gross requirements | 100 | 200 | 120 | 180 | 60 | |||||
| Scheduled receipts | ||||||||||
| Projected on-hand inventory | 20 | 200 | 200 | 0 | 0 | 240 | 60 | 0 | 0 | 0 |
| Planned receipts | 280 | 360 | ||||||||
| Planned order releases | 280 | 360 |
20
Figure 11.27
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Solved Problem 3
| Item: C | Lot Size: L4L Lead Time: 2 weeks | |||||||||
| Week | ||||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Gross requirements | 200 | 400 | 240 | 360 | 120 | |||||
| Scheduled receipts | 200 | |||||||||
| Projected on-hand inventory | 200 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Planned receipts | 400 | 240 | 360 | 120 | ||||||
| Planned order releases | 400 | 240 | 360 | 120 |
0
Figure 11.27
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Solved Problem 3
| Item: D | Lot Size: FOQ = 500 units Lead Time: 1 week | |||||||||
| Week | ||||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| Gross requirements | 400 | 240 | 360 | 120 | ||||||
| Scheduled receipts | ||||||||||
| Projected on-hand inventory | 425 | 25 | 25 | 285 | 425 | 305 | 305 | 305 | 305 | 305 |
| Planned receipts | 500 | 500 | ||||||||
| Planned order releases | 500 | 500 |
425
Figure 11.27
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Solved Problem 4
The Pet Training Academy offers a 5-day training program for troubled dogs. As seen below, the training process requires 5 days, beginning with the dog’s arrival at 8 A.M. on day one, and departure after a shampoo and trim, at 5 P.M. on day five.
| Pet Training Academy Process | Lead Time in Days |
| Level 1: Departure Day | 1 |
| Level 2: 3rd Day | 1 |
| Level 3: 2nd Day | 2 |
| Level 4: Arrival Day | 1 |
| Total | 5 |
Table 11.5
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Solved Problem 4
To adequately train a dog, the Academy requires Training Coaches, Dog Groomers, a Dog Dietician, Care Assistants, and Boarding Kennels where the dogs rest.
The time required by each employee and resource classifications by process level is given below:
| Pet Training Academy Process Resources Required | Training Coach (Hours) | Dog Dietician ( Hours) | Care Assistant (Hours) | Boarding Kennel (Hours) |
| Level 1: Departure Day | 2 | 1 | 1 | 12 |
| Level 2: 3rd Day | 3 | 1 | 2 | 24 |
| Level 3: 2nd Day | 3 | 1 | 2 | 24 |
| Level 4: Arrival Day | 2 | 1 | 1 | 12 |
Table 11.6
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Solved Problem 4
The master schedule for the trained dogs is shown below, noting that departures for trained dogs are actual departures for days 1-5 and forecasted departures for days 6-12.
| Day of the month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Master Schedule of Trained Dogs | 5 | 2 | 2 | 8 | 3 | 0 | 1 | 8 | 4 | 3 | 6 | 0 |
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Solved Problem 4
Use the above information to calculate the daily resource requirements in hours for employees in each category, and the hours of boarding room needed to train the dogs.
Assuming that each boarding kennel is available for 24 hours in a day, how many kennels will be required each day?
Assuming that each employee is able to work only eight hours per day, how many people in each employee category will be required each day?
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Solved Problem 4
Figure 11.28
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Solved Problem 4
The previous table shows the number of dogs at each level during their stay at the Pet Training Academy.
The top row of each level shows the number of dogs who will advance to the next level at the end of the day.
The daily resource requirements for each resource required to train the departing dogs are shown in the following slide.
Total number of CA hours Projected for Day 2
[1(2) + 2(2) + 2(11) +1(0)] = 28 hours
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Solved Problem 4
| Day of the Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Training Coach Hours required | 52 | 43 | 39 | 44 | 41 | 45 | 59 | 55 | 35 | 24 | 12 | 0 |
| Dog Dietician hours required | 20 | 15 | 14 | 20 | 16 | 16 | 22 | 21 | 13 | 9 | 6 | 0 |
| Care Assistant hours required | 32 | 28 | 25 | 24 | 25 | 29 | 37 | 34 | 22 | 15 | 6 | 0 |
| Boarding kennels hours required | 384 | 336 | 300 | 288 | 300 | 348 | 444 | 408 | 264 | 180 | 72 | 0 |
| Number of Boarding Kennels required | 16 | 14 | 13 | 12 | 13 | 15 | 19 | 17 | 11 | 8 | 3 | 0 |
Table 11.7
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Solved Problem 4
The number of boarding kennels required per day (note all fractional kennels are rounded to the next higher integer) are obtained by dividing the total number of hours needed for boarding kennels by 24, and are shown in the last row of the previous slide.
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Solved Problem 4
The number of people required per day in each employee category are obtained by dividing the resource requirements by working hours in each day. They are shown below. Note that all fractional employees are rounded to the next higher integer.
| Number of Employee Required per Day | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Training Coaches | 7 | 6 | 5 | 6 | 6 | 6 | 8 | 7 | 5 | 3 | 2 | 0 |
| Dog Dieticians | 3 | 2 | 2 | 3 | 2 | 2 | 3 | 3 | 2 | 2 | 1 | 0 |
| Care Assistants | 4 | 4 | 4 | 3 | 4 | 4 | 5 | 5 | 3 | 2 | 1 | 0 |
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This Week’s Discussions
UPS – we all know that UPS is a package delivery company, but do we know how they have transformed their industry?
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