JAWABAN LATIHAN SOAL MID-TEST OPERATION MANAGEMENT ... 4.7 Using
MAD for this problem,. (4). (6). (3). Marketing. (5). Operations. (1). (2). Marketing ...
JAWABAN LATIHAN SOAL MID-TEST OPERATION MANAGEMENT CASE STUDY Minit-Lube Inc. Minit-Lube, Inc. 1. (a) What constitutes the mission of Minit-Lube? To provide economical preventative maintenance and in-terior auto cleaning, primarily to vehicles owned by indi-viduals (as opposed to businesses), in the U.S. (b) How does the Minit-Lube strategy provide competitive advantage? 2. This case is a good way to get the student thinking about the 10 decisions around which the text is organized. Minit-Lube’s approach to these 10 decisions includes: Product Design: A narrow product strategy could be defined as “lubricating automobiles” (more in Chapter 5). Quality Strategy: Because of limited task variety, high repetition, good training, and good manuals, quality should be relatively easy to maintain. Process Strategy: The process strategy allows employees and capital invest-ment to focus on doing this mission well, rather than trying to be a “general purpose” garage or gas station. Location Strategy: Facilities are usually located near residential areas. Layout Strategy: The three bays are designed specifically for the lubrication and vacuuming tasks to minimize wasted movement on the part of the employees and to contribute to the speedier service. Supply Chain Strategy: Purchasing is facilitated by negotiation of large purchases and custom packaging. Human Resources Strategy: Human resources strategy focuses on hiring a few employees with limited skills and training them in a limited num-ber of tasks during the performance of which they can be closely supervised. Inventory: Inventory investment should be relatively low, and they should expect a high turnover. Scheduling: Scheduling is quite straightforward with similar times for most cars. Once volume and fluctuation in volume are determined, scheduling should be very direct—assisting both staffing and customer relations. Maintenance: There is relatively little equipment to be maintained, therefore little preventive maintenance required. With three bays and three systems, there is backup available in the case of failure. 3. Specialization of personnel and facilities should make Minit-Lube more efficient. Jobs/tasks accomplished per man hourwould be a good place to start.
4.7 Using MAD for this problem,
(1) Year 1 2 3 4 5
(2) Sales 167,325 175,362 172,536 156,732 176,325
(4) (6) (3) Marketing (5) Operations Marketing VP’s Error Operations VP’s Error VP’s Forecast [(2)–(3)] VP’s Forecast [(2)–(5)] 170,000 2,675 160,000 7,325 170,000 5,362 165,000 10,362 180,000 7,464 170,000 2,536 180,000 23,268 175,000 18,268 165,000 11,325 165,000 11,325 Totals 50,094 49,816
MAD (marketing VP) = 50,094/5 = 10,018.8. MAD (operations VP) = 49,816/5 = 9,963.2. Therefore, based on past data, the VP of operations has been presenting better forecasts.
4.8 (a)
(96 88 90) 3
91.3
Table for Problem 4.9 (a, b, c) Forecast
Month January February March April May June July August September October November December
Price per Chip $1.80 1.67 1.70 1.85 1.90 1.87 1.80 1.83 1.70 1.65 1.70 1.75
Two-Month Moving Average
1.735 1.685 1.775 1.875 1.885 1.835 1.815 1.765 1.675 1.675
|Error|
Three-Month Moving Average
Two-Month Moving Average
Three-Month Moving Average
1.723 1.740 1.817 1.873 1.857 1.833 1.777 1.727 1.683 Totals
.035 .165 .125 .005 .085 .005 .115 .115 .025 .075 .750
.127 .160 .053 .073 .027 .133 .127 .027 .067 .793
(b)
(88 90) 2
89
(c) Temperature 2 day M.A. |Error| (Error)2 — — 93.5 93.5 94.0 95.5 92.0
93 94 93 95 96 88 90
— — 0.5 1.5 2.0 7.5 2.0 13.5
— — 0.25 2.25 4.00 56.25 4.00 66.75
Absolute % Error — — 100(.5/93) 100(1.5/95) 100(2/96) 100(7.5/88) 100(2/90)
= 0.54% = 1.58% = 2.08% = 8.52% = 2.22% 14.94%
MAD = 13.5/5 = 2.7
(d) MSE = 66.75/5 = 13.35 (e) MAPE = 14.94%/5 = 2.99% 4.9 (a, b) The computations for both the two- and three-month averages appear in the table; the results appear in the figure below.
(c) MAD (two-month moving average) = .750/10 = .075 MAD (three-month moving average) = .793/9 = .088 Therefore, the two-month moving average seems to have performed better.
Table for Problem 4.9 (a, b, c) Forecast
Month January February March April May June July August September October November December
Price per Chip $1.80 1.67 1.70 1.85 1.90 1.87 1.80 1.83 1.70 1.65 1.70 1.75
Two-Month Moving Average
1.735 1.685 1.775 1.875 1.885 1.835 1.815 1.765 1.675 1.675
|Error|
Three-Month Moving Average
Two-Month Moving Average
Three-Month Moving Average
1.723 1.740 1.817 1.873 1.857 1.833 1.777 1.727 1.683 Totals
.035 .165 .125 .005 .085 .005 .115 .115 .025 .075 .750
.127 .160 .053 .073 .027 .133 .127 .027 .067 .793
Plan C
13.5 (a)
Period
Demand
Production
Ending Inv.
0 1 2 3 4 5 6 7 8
1,400 1,600 1,800 1,800 2,200 2,200 1,800 1,400
1,775 1,775 1,775 1,775 1,775 1,775 1,775 1,775
200 575 750 725 700 275 0 0 375
Stockouts (Units)
All other things being equal, it would appear that Plan C, with a cost of $85,500, should be recommended over Plan A (cost = $140,000) or Plan B (cost = $214,000).
(b)
12.9 D
15,000, H
(a) EOQ
$25/unit/year, S
2DS H
2 15,000 25
75
$75 300 units
(b) Annual holding costs (Q/2) H (300/2) 25 $3,750 (c) Annual ordering costs (D/Q) S (15,000/300) 75 $3,750 (d)
ROP = d
L
15,000 units 300 days
8 days
400 units
12.10 Reorder point demand during lead time 100 units/day 21 days 2,100 units
Extra Cost
11,500 15,000 14,500 14,000 5,500 150 15,000 25 2,500 7,500 Total Extra Cost: $85,500
12.11 D 10,000 Number of business days 300 Lead time 5 days ROP [Demand/Day](Lead time) 166.67 167 units.
[10,000/300](5)
14.11 (a)
Week
Item A H C
(b)
1
2
3
4
5
6
Gross req Order rel
7 100
Gross req Order rel 100
1
Parent: — Lead Time: 1 2 3
4
5
100
6
100 50
Gross requirement Scheduled receipt On hand Net requirement 50 Planned order receipt Planned order release
50
100 50
1
4
5
6
1
Parent: A, H Lead Time: 2 2 3
4
5
50
6
100
12 150
150 50 50 150
Quantity: Lot Size: L4L 7 8 9
10
11
100
50
150
0 100 100
0 50 50
0 150 150
100
Parent: — Lead Time: 1 2 3
11
50
50
50 150
50
Quantity: Lot Size: L4L 7 8 9
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
Level: 1 Item: C Week No.
10
100
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
Level: 0 Item: H Week No.
9
100
Gross req Order rel
Level: 0 Item: A Week No.
8 100
12
150
10
11
100
50
0 100 100
0 50 50
100
50
Quantity: 1X Lot Size: L4L 7 8 9
10
11
100
100
50
50
150
50 50 50 50
0 100 100 50
0 50 50 150
0 50 50
0 150 150
12
12
14.12
Net material requirements plan: Week
Item
1
A
Gross requirement On hand: – Net requirement Order receipt Order release
H
Gross requirement On hand: – Net requirement Order receipt Order release
2
3
4
5
6
7
8
9
100 0 100 100 100
10 50 0 50 50
50
150 50 0 50 50 50
B
Gross requirement On hand: 100 Net requirement Order receipt Order release
100 100
50 0 50 50 150
C
Gross requirement On hand: 50 Net requirement Order receipt Order release
100 50 50 50 50
J
Gross requirement On hand: 100 Net requirement Order receipt Order release
100 100 0 0 50
50 0 50 50
K
Gross requirement On hand: 100 Net requirement Order receipt Order release
100 100 0 0 50
50 0 50 50
D
Gross requirement On hand: 50 Net requirement Order receipt Order release
50 50
E
Gross requirement On hand: 75 Net requirement Order receipt Order release
50 75
F
Gross requirement On hand: 75 Net requirement Order receipt Order release
G
Gross requirement On hand: 75 Net requirement Order receipt Order release
50
100
100 0 100 100 50
50 0 50 50 150
150 0 150 150 150
50 75
75
50 50 75
75
100 25 75 75
150 0 150 150
75
150
100 25 75 75 100
50 0 50 50 150
100 0 100 100
150 0 150 150
100 25 75 75 50
50 0 50 50 100
100 0 100 100 150
150 0 150 150
150 0 150 150 50 0 50 50
12 150 0 150 150
100 0 100 100 100
50
11
150 0 150 150
14.13 (a)
(b)
(c)
Level: 0 Item: 20 fan Week No.
1
Parent: — Lead Time: 1 2 3
4
5
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 1 Item: housing Week No.
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
9
10
11
12
Quantity: 1X Lot Size: L4L 7 8
9
10
11
12
Quantity: 2X Lot Size: 500 7 8
9
10
11
12
1000 100 900 900 900
1
Parent: 20 fan Lead Time: 1 week 2 3 4
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 1 Item: grills Week No.
6
Quantity: Lot Size: 7 8
5
6 900 100 800 800
800
1
Parent: 20 fan Lead Time: 2 weeks 2 3 4
5
6 1800 200 1600 2000
2000
400
Level: 1 Item: fan assembly Week No.
Parent: 20 fan Lead Time: 3 weeks 1 2 3 4
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 1 Item: electrical unit Week No.
Parent: 20 fan Lead Time: 1 week 1 2 3 4
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
12
Quantity: 1X Lot Size: L4L 7 8
5
9
10
11
12
6
Quantity: 1X Lot Size: L4L 7 8
9
10
11
12
6
Quantity: 2X Lot Size: 100 7 8
9
10
11
12
6
Quantity: 1X Lot Size: 500 7 8
9
10
11
12
Quantity: 1X Lot Size: L4L 7 8
9
10
11
12
6 900
900 900 900
1
Parent: housing Lead Time: 2 weeks 2 3 4
5 800
800 800 800
1
Parent: housing Lead Time: 1 week 2 3 4
5 1600 50 1550 1600
1600
1
Parent: housing Lead Time: 1 week 2 3 4
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 2 Item: hub Week No.
11
750
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 2 Item: handle Week No.
10
150 750 750
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 2 Item: supports Week No.
9
6 900
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 2 Item: frame Week No.
5
Quantity: 1X Lot Size: L4L 7 8
5 800 400 400 500
100
500
1
Parent: fan assembly Lead Time: 1 week 2 3 4 5 750
750 750 750
6
Level: 2 Item: blades Week No.
1
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
Parent: fan assembly Lead Time: 2 weeks 2 3 4
10
11
12
6
Quantity: 1X Lot Size: L4L 7 8
9
10
11
12
6
Quantity: 1X Lot Size: 12 7 8
9
10
11
12
Quantity: 1X Lot Size: 25 7 8
9
10
11
12
50
3800
1
Parent: electrical unit Lead Time: 1 week 2 3 4 5 900
900 900 900
Level: 2 Item: switch Week No.
1
Parent: electrical unit Lead Time: 1 week 2 3 4 5
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
900 20 880 888
8
888
Level: 2 Item: knob Week No.
1
Parent: electrical unit Lead Time: 1 week 2 3 4 5
Gross requirement Scheduled receipt On hand: 20 Net requirement Planned order receipt Planned order release
0 1 2 2 3 1 2 2 3 3
9
3750 3800
Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release
Level
6
3750
Level: 2 Item: motor Week No.
14.14 (a)
5
Quantity: 5X Lot Size: 100 7 8
900 200 200
200
200 700
700 Component
Quantity
A B C D E F G H E C
1 1 1 1 1 1 1 1 1 1
6
(b) Lot Size
Lead Time
Onhand
Safety Stock
Lot for Lot
1
0
—
Lot Size Lot for Lot
Lot Size Lot for Lot
Lot Size Lot for Lot
Lead Time 1
Lead Time 1
Lead Time 1
A
2
—
—
Onhand
Safety Stock
Allocated
5
—
—
Onhand
Safety Stock
Allocated
5
—
—
Safety Stock
Lot for Lot
3
1
—
1
0
Allocated
Onhand
Lot for Lot
—
Safety Stock
Lead Time
Lead Time
Item ID
Onhand
Lot Size
Lot Size
Allocated
Low Level Code
Low Level Code 1
Low Level Code 1
Low Level Code 2
B
Allocated
Item ID
—
2
G
Safety Stock
Allocated
10
—
—
Low Level Code 2
Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
7
Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
2
3
Period (week) 4 5 6
7
2
2
2
2
2
8 A
2 8 8
0
8
2
3
Period (week) 4 5 6
7 10
5
5
5
5
5
5
8 A
5 5 5
0
5
2
3
Period (week) 4 5 6 8
5
5
5
5
5
7
8
0
0
7
8
0
0
7
8
5
5
B
5 3 3
3
2
3
Period (week) 4 5 6 5F
1
1
1
1
1
1 4 4
4
1 Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
2
10
1 Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
8
10
1
Item ID H
Period (week) 4 5 6
0 10 10
1
Item ID D
3
10
1
Item ID F
2
Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
Item ID
Low Level Code
Onhand
1
2
3
Period (week) 4 5 6 5
10
10
10
10
10
0
F
10 0 0
Lot Size
Lead Time
Lot for Lot
1
Lot Size
Lead Time
Lot for Lot
1
Onhand
Safety Stock
Allocated
10
—
—
Onhand
Safety Stock
Allocated
4
—
—
Low Level Code 3
Low Level Code 3
Item ID C
1 Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
3
Period (week) 4 5 6
7
8
2
2
7
8
1
1
1
Period (week) 4 5 6
7
0 10
Item ID E
2
1 Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
10
2
10
10
0
0
3
10 0 0
4
4
8 10 0 0
Period (week) 4 5 6 3
4
H
4
B
H,D
3 0 0
0
Ten units are required for production, and 10 each of B and F for field service repair Component
Quantity
A B C D E F G H
10 20 40 20 40 20 20 20
Component
Quantity
A B C D E F G H
10 18 13 13 14 15 14 5
Lot Size
Lead Time
Onhand
Safety Stock
Lot for Lot
1
0
—
Allocated
Low Level Code
Item ID
—
0
A
1 Gross requirements Scheduled receipts Projected-on-hand Net requirements Planned receipts Planned releases
2
3
8 10
0
0
0
0
0
0
0
10
10 10 10