Question

We are thinking about layout strategies for production now. This is a problem about workstation layout.

A firm must produce 40 units/day during an 8-hour workday. Tasks, times, and predecessor activities are given below. You want to group the tasks below into workstations, each workstation staffed by one person.

Task	Time (Minutes)	Predecessor(s)
A	2	-
B	2	A
C	8	-
D	6	C
E	3	B
F	10	D, E
G	4	F
H	3	G
Total	38 minutes

                       

A) What is the cycle time you would need in order to produce your target of 40 units during 8 hours?

B) Use the cycle time you computed in part A above. What is the minimum number of workstations you would need in order to achieve this cycle time at all workstations?

C) Suggest a workstation grouping which would work. In your answer, clearly specify which tasks you would assign to which station. For example, you might want to put Tasks A, B, C, and D together in Workstation 1. Determine the cycle time and the appropriate number of workstations to produce the 40 units per day.

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Answer 1

answer:

A)

Production time per day= 8*60 = 480 minutes

Target production output per day = 40 units

Cycle time = (Production time per day) / (Target production output per day) = 480/ 40 = 12 minutes

Cycle time to produce 40 units during 8 hours is 12 minutes

B)

Sum of total task times= 38 minutes

Number of workstations = (Sum of total task times)/ (cycle time) = 38 mins / 12 mins = 3.17 = 4 (rounded)

Minimum 4 workstations are needed to achieve the cycle time of all workstations.

C)

Now we have to determine how tasks will be assigned to workstations. In general, we have to use rule that prioritizes tasks according to the largest number of followers or based on the task time.

Based on the rule "prioritizes tasks according to the largest number of followers or based on the task time", balance is made in the below table to detail out grouping of tasks under each workstation

Cycle time is 12 minutes and appropriate number of workstation to produce 40 units per day is 4.

Efficiency of the production line can also be calculated as below-

Efficiency= (Sum of all task times)/ (Actual no. of workstations)*(Cycle time)

Efficiency= (38)/ (4)*(12) = 79.17%