Question: Sturgill Manufacturing, Inc. needs to predict the numbers of machines and employees required to produce its planned production for the coming year. The plant runs three shifts continuously during the workweek, for a total of 120 hours of capacity per week. The shop efficiency (the percent of total time available for production), which accounts for setups, changeovers, and maintenance, averages 70% with a standard deviation of 5%, which reduces the weekly capacity. Six key parts are produced, and the plant has three different types of machines to produce each part. The machines are not interchangeable as they each have a specific function. The time to produce each part on each machine varies. The mean time and standard deviation (in hours) to produce each part on each machine are shown below:
|
Mean Time
|
|
|
|
|
Part Type
|
Machine A
|
Machine B
|
Machine C
|
|
1
|
3.5
|
2.6
|
8.9
|
|
2
|
3.4
|
2.5
|
8
|
|
3
|
1.8
|
3.5
|
12.6
|
|
4
|
2.4
|
5.8
|
12.5
|
|
5
|
4.2
|
4.3
|
28
|
|
6
|
4
|
4.3
|
28
|
Standard Deviation
|
Part Type
|
Machine A
|
Machine B
|
Machine C
|
|
1
|
0.15
|
0.12
|
0.15
|
|
2
|
0.15
|
0.12
|
0.15
|
|
3
|
0.1
|
0.15
|
0.25
|
|
4
|
0.15
|
0.15
|
0.25
|
|
5
|
0.15
|
0.15
|
0.5
|
|
6
|
0.15
|
0.15
|
0.5
|
The forecasted demand is shown below
|
Part Type
|
Demand (Parts/Week)
|
|
1
|
42
|
|
2
|
18
|
|
3
|
6
|
|
4
|
6
|
|
5
|
6
|
|
6
|
6
|
Machines A and B only require one person to run two machines. Machine C requires only one person per machine. Develop a simulation model to determine how many machines of each type and number of employees will be required to meet the forecasted demand.