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Novelly Sionita Simanjuntak

0906557190

9.2 Dik: annual demand = $2.000.000

Transit time I (t1)= 10 days

Transit time II (t2) = 7 days

Dit: reduction in transit inventory

Jawab: reduction in transit inventory = transit inventory I transit inventory II

Transit inventory I =

Transit inventory I =

Maka, Transit inventory I = $ 54.794, 5

Transit inventory II =

Transit inventory II =

Maka, Transit inventory II = $ 38.356,1

Diperoleh reduction in time inventory = $ 54.794,5 - $ 38.356,1 = $ 16.438,4

9.4 Dik: Average inventory = $ 10.000

Capital cost = 10%

Storage cost = 25%

Risk cost = 50%

Dit: Annual carrying cost

Jawab: Total cost of carrying inventory = 10% + 25% + 50% = 85%

So, Annual carrying cost of inventory =85% x $ 10.000 = $ 8.500

9.6 Dik: Wages for purchasing = $ 45.000

Purchasing expenses = $ 30.000

Custom and brokerage cost = $ 25 per order

Cost of financing inventory = 8%

Storage cost = 6%

Risk cost = 10%

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Average inventory = $ 250.000

Annual order = 5000

Dik: annual ordering and carrying cost

Jawab: annual order cost

Annual ordering cost = wages for purchasing + purchasing expenses + (annual order x $25)

= $ 45.000 + $ 30.000 + (5000 x $25)

= $ 45.000 + $ 30.000 + $ 125.000 = $ 200.000

Annual carrying cost

Total cost of carrying inventory = 8% + 6% + 10% = 24%

Annual carrying cost = 24% x $ 250.000 = $ 60.000

9.8 tanpa safety stock

Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total unit Total $

Forecast Demand 5000 8000 8000 9000 30000

Production 7500 7500 7500 7500 30000

Ending Inventory 0 2500 2000 1500 0

Average Inventory 1250 2250 1750 750

Inventory Cost ($) 7500 13500 10500 4500 36.000

Production planning for each quarter = 30.000/4 = 7

Average inventory = (ending inventory sebelum + ending inventory sekarang) : 2

Inventory cost = average inventory x carrying cost per unit

Dengan safety stock = 100 (asumsi: opening inventory tetap 0)

Quarter 1 Quarter 2 Quarter 3 Quarter 4 Total unit Total $

Forecast Demand 5000 8000 8000 9000 30000

Production 7525 7525 7525 7525 30100

Ending Inventory 0 2525 2050 1575 100

Average Inventory 1262.5 2287.5 1812.5 837.5

Inventory Cost ($) 7575 13725 10875 5025 37.200

Total production = total demand + ending inventory opening inventory

= 30000+100-0 =30100

Production plan for each quarter= 30100/4 = 7525

9.10 Assets = liabilities + owners equity

Owners equity = assets liabilities = $ 2.000.000 - $ 1.600.000 = $ 400.000

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9.12 Revenue $ 3.000.000

Cost of good sold

Direct labor $ 700.000

Direct material $ 900.000

Factory overhead $ 700.000 $ 2.300.000

Gross Margin $ 700.000

General and admin expenses $ 300.000

Net Income $ 400.000

9.14 Dik: Annual cost of good sold = $ 12.000.000

Average inventory = $ 2.500.000

Jawab:

a. Inventory turns ratio =Annual cost of good sold : Average inventory=

b. Inventory turns = Annual cost of good sold : Average inventoryAverage inventory = Annual cost of good sold : Inventory turns

Average inventory =

Reduction in average inventory = $ 2.500.000 - $ 1.200.000 = $ 1.300.000

c. Cost savings = reduction in inventory x 20%Cost savings = $ 1.300.000 x 20% = $ 260.000

9.16 Dik: on hand inventory = 600 units

Annual usage = 7200 units

Working days = 240 days

Dit: Days of supply

Jawab: Average daily usage =

Days of supply =

9. 18

Part Number Annual unit usage unit cost $ Annual $ usage

1 200 10 2000

2 15000 4 60000

3 60000 6 360000

4 15000 15 225000

5 1400 10 14000

6 100 50 5000

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7 25000 2 50000

8 700 3 2100

9 25000 1 25000

10 7500 1 7500

Part

Number

Annual $

usage

cumulative

$ usage

cumulative %

$ usage

Cumulative

% of items Class

3 360000 360000 47.96% 10 A

4 225000 585000 77.94% 20 A

2 60000 645000 85.93% 30 B

7 50000 695000 92.59% 40 B

9 25000 720000 95.92% 50 B

5 14000 734000 97.79% 60 C

10 7500 741500 98.79% 70 C

6 5000 746500 99.45% 80 C

8 2100 748600 99.73% 90 C

1 2000 750600 100.00% 100 C

Analisis:

High priority = part 3 dan 4

Medium priority = part 2, 7 dan 9

Lowest priority = Part 5, 10, 6, 8 dan 1

0

0.2

0.4

0.6

0.8

1

1.2

10 20 30 40 50 60 70 80 90 100

percentageo

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value

percentage of items

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