A company needs to rebalance a product layout for producing new plastic license plates. They plan to use the assembly line six hours in order to meet projected demand of 2,160 license plates each day. The following table describes the tasks involved in the production of this product:
For output to equal projected demand, what is the theoretical minimum number of workstations needed?
A) 2
B) 2.8
C) 3
D) 4
E) 5

Question

A company needs to rebalance a product layout for producing new plastic license plates. They plan to use the assembly line six hours in order to meet projected demand of 2,160 license plates each day. The following table describes the tasks involved in the production of this product: 
For output to equal projected demand, what is the theoretical minimum number of workstations needed?
A) 2 
B) 2.8 
C) 3 
D) 4 
E) 5

Quizplus · Accepted Answer

To find the theoretical minimum number of workstations, we need to calculate the minimum cycle time first. 
Minimum cycle time = longest task time = 0.6 minutes 
Theoretical minimum number of workstations = Total task time / Minimum cycle time
Total task time = 3.3 + 1.1 + 0.3 + 0.5 + 1.2 + 0.6 + 0.4 + 0.8 = 8.2 minutes
Theoretical minimum number of workstations = 8.2 / 0.6 = 13.67
Since the number of workstations must be a whole number, we round up to the nearest integer, which gives us 14. However, some of the workstations would be idle for a significant amount of time, so we can try to reduce the number of workstations to minimize the idle time. 
By analyzing the tasks, we can see that tasks 1, 3, and 7 can be grouped together because they have a total task time of only 1.6 minutes, which is less than the cycle time. Similarly, tasks 2, 4, and 5 can be grouped together because they have a total task time of only 1.9 minutes. Finally, tasks 6 and 8 can be grouped together because they have a total task time of only 1.8 minutes. 
So, we can have three workstations: 
Workstation 1: tasks 1, 3, and 7 (total task time = 1.6 minutes)
Workstation 2: tasks 2, 4, and 5 (total task time = 1.9 minutes)
Workstation 3: tasks 6 and 8 (total task time = 1.8 minutes)
The cycle time for each workstation would be set by the longest task time in the workstation. 
Workstation 1: cycle time = 0.6 minutes 
Workstation 2: cycle time = 0.7 minutes 
Workstation 3: cycle time = 0.6 minutes 
The total cycle time for all workstations would be 1.9 minutes, which is less than the available time of 6 hours or 360 minutes. Therefore, three workstations would be needed to meet the projected demand of 2,160 license plates per day.

A Company Needs to Rebalance a Product Layout for Producing