Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Houma Containers, Inc., makes industrial fiberglass tanks that are used on offsh

ID: 379470 • Letter: H

Question

Houma Containers, Inc., makes industrial fiberglass tanks that are used on offshore oil platforms. Demand for the next four months and capacities of the plant are shown in the table below. Unit cost on regular time is $400. Overtime cost is 150% of regular time cost. Subcontracting is available in substantial quantity but at a very high cost, $1100 per unit. Holding costs are $200 per tank per month; back orders cost the firm $1000 per unit per month. Houma's management believes that the transportation algorithm can be used to optimize this scheduling problem. The firm has no beginning inventory and anticipates no ending inventory.

March

April

May

June

Demand

300

500

300

350

Regular capacity

200

200

250

250

Overtime capacity

50

50

50

50

Subcontract cap.

150

100

100

150

a. How many units will be produced on regular time in June?

b. How many units will be produced by subcontracting over the four-month period?

c. What will be the inventory at the end of April?

d. What will be total production from all sources in April?

e. What will be the total cost of the optimum solution?

f. Does the firm utilize the expensive options of subcontracting and back ordering? When; why?

March

April

May

June

Demand

300

500

300

350

Regular capacity

200

200

250

250

Overtime capacity

50

50

50

50

Subcontract cap.

150

100

100

150

Explanation / Answer

Houma Containers

March

April

May

June

SUPPLY

March regular time

400

600

800

1,000

200

March overtime

600

800

1,000

1,200

50

March subcontracting

1,100

1,300

1,500

1,700

150

April regular time

1,400

400

600

800

200

April overtime

1,600

600

800

1,000

50

April subcontracting

2,100

1,100

1,300

1,500

100

May regular time

2,400

1,400

400

600

250

May overtime

2,600

1,600

600

800

50

May subcontracting

3,100

2,100

1,100

1,300

100

June regular time

3,400

2,400

1,400

400

250

June overtime

3,600

2,600

1,600

600

50

June subcontracting

4,100

3,100

2,100

1,100

150

DEMAND

300

500

300

350

Solution

Optimal Cost =

$935,00

March

April

May

June

DUMMY

March regular time

100.

100.

March overtime

50.

March subcontracting

150.

April regular time

200.

April overtime

50.

April subcontracting

100.

May regular time

250.

May overtime

50.

May subcontracting

50.

0.

50.

June regular time

250.

June overtime

50.

June subcontracting

50.

100.

Hence, from the above table answers are:

a.250 units will be produced on regular time in June

b. 350 units will be produced by subcontracting over the four-month period

c. 0, and 50 units are back ordered

d. 350 units will be total production from all sources in April

e. $935,000 (the total cost of optimum solution)

f. They use subcontracting every month; there are back orders in April filled with May production. The firm has so little excess capacity, even with the short-termoptions, that it must utilize almost every unit available, which forces the use of the more expensive options.

March

April

May

June

SUPPLY

March regular time

400

600

800

1,000

200

March overtime

600

800

1,000

1,200

50

March subcontracting

1,100

1,300

1,500

1,700

150

April regular time

1,400

400

600

800

200

April overtime

1,600

600

800

1,000

50

April subcontracting

2,100

1,100

1,300

1,500

100

May regular time

2,400

1,400

400

600

250

May overtime

2,600

1,600

600

800

50

May subcontracting

3,100

2,100

1,100

1,300

100

June regular time

3,400

2,400

1,400

400

250

June overtime

3,600

2,600

1,600

600

50

June subcontracting

4,100

3,100

2,100

1,100

150

DEMAND

300

500

300

350