Operations Management Question Essay

1152 Words Dec 3rd, 2012 5 Pages
FALL 2011 2011

Deadline: October 26,

Middle East Technical University – Northern Cyprus Campus

BUS 361 Operations Management

Homework 1 - Solutions

1. Fruit Computer Company manufactures memory chips in lots of ten chips. From past experience, Fruit knows that 80% of all lots contain 10% (1 out of 10) defective chips, 20% of all lots contain 50% (5 out of 10) defective chips. If a good batch (that is, 10% defective) of chips is sent on to the next stage of production, processing costs of $1000 are incurred, and if a bad batch (that is, 50% defective) is sent on to the next stage of production, processing costs of $4000 are incurred. Fruit also has the alternative of reworking a batch at a cost of $1000. A reworked batch is
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d. What is W0 (critical WIP) for this line?

Station 1 Production rate (jobs/min) Production rate (jobs/day) = 128

Station 2

Station 3

= 160

= 160

a. Station 1 is the bottleneck station, which has bottleneck rate, rb = 4/15. b. Because the bottleneck station’s production rate of 128 is less than the daily demand of 180 units, this system cannot satisfy the daily demand.

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c. T0 = 15 + 30 + 3 = 48 minutes.

d. W0 = rb * T0 = 4/15 * 48 = 12.8

13 units.

5. The final assembly of Noname PCs requires a total of 12 tasks. The assembly is done at the Lubbock, Texas plant using various components imported from Far East. The tasks required for the assembly operations, task times and precedence relationships between tasks are as follows:

Task

Task Time (min)

Immediate Predecessors 1 2 2 2 2 3, 4 7 5 6, 9 8, 10 11

Positional Weight 70 58 31 27 20 29 25 18 18 17 13 7

Rank

1 2 3 4 5 6 7 8 9 10 11 12

12 6 6 2 2 12 7 5 1 4 6 7

1 2 3 5 7 4 6 8 9 10 11 12

Given that the company produces one assembled PC every 15 minutes,

a. Assign tasks to workstations using the Ranked Positional Weight Algorithm. b. Calculate balance delay and workload imbalance for your solution. c. Evaluate optimality of your solution (in terms of number of workstations, balance delay and workload imbalance).

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a. Order of tasks: 1, 2, 3, 6, 4, 7, 5, 8, 9, 10, 11, 12

WS 1 1 15 3

WS 2 2, 3, 4 15 9 3 1

WS 3

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