jawaban latihan soal mid-test operation management - yimg.com

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



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


1.735 1.685 1.775 1.875 1.885 1.835 1.815 1.765 1.675 1.675

|Error|




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


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


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


100 50 50 50 50

J


100 100 0 0 50

50 0 50 50

K


100 100 0 0 50

50 0 50 50

D


50 50

E


50 75

F


G


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


4

5

Gross requirement Scheduled receipt On hand Net requirement Planned order receipt Planned order release Level: 1 Item: housing Week No.


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


12


5

9

10

11

12

6


9

10

11

12

6


9

10

11

12

6


9

10

11

12


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


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


Parent: fan assembly Lead Time: 2 weeks 2 3 4

10

11

12

6


9

10

11

12

6


9

10

11

12


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


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


Level

6

3750

Level: 2 Item: motor Week No.

14.14 (a)

5


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



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


7


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


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


Item ID

Low Level Code

Onhand

1

2

3


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


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


10

2

10

10

0

0

3

10 0 0

4

4

8 10 0 0


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


2

3

8 10

0

0

0

0

0

0

0

10

10 10 10