Question

Sue Helms Appliances wants to establish an assembly line to manufacture its new​ product, the Micro Popcorn Popper. The goal is to produce five poppers per hour. The​ tasks, task​ times, and immediate predecessors for producing one Micro Popcorn Popper are as​ follows:
Task Performance time(minutes) Predecessor
A 8 -
B 10 A
C 8 A,B
D 10 B,C
E 8 C
F 4 D,E

a. The theoretical minimum number of workstations is:___________
b. The assignment of tasks to workstations should be:________

Were you able to assign all the activities to workstations equivalent to the theoretical minimum workstation ?

c. The efficiency of the assembly line is:________

Answer 1

Answer:

Please see explanation below.

Explanation:

a. Cycle time = Production time available per hour / Units required per hour

= 60 / 5

= 12minutes

Minimum number of workstations = Sum of the task time / Cycle time

Sum of task time

= 8 + 10 + 8 + 10 + 8 + 4

= 48

The theoretical minimum number of work stations is

= 48 / 12

= 4

b. In order to assign the tasks to the work station, events that precede the task must be considered together with the time taken to complete each task.

°Task A This task is assigned to work station 1 and no task would further be assigned to work station 1, otherwise it will exceed the cycle time.

°Task B. This next task will be assigned to work station 2, no additional task will be assigned to station 2.

Task C is assigned to workstation 3, hence can no longer accept any other assigned task.

°Task D is the next task and will be assigned to work station 4, and we cannot assign any more task to work station 4.

°Task E and F will not be assigned as there are no more available stations.

Task Time Workstation

A. 8 1

B. 10 2

C. 8 3

D. 10 4

E. 8 -

F. 4 -

Please note that due to the theoretical minimum number of work station, which is 4, it will not be possible to assign task to all the workstations hence task E and F remains unassigned.

C. Efficiency of the assembly line

Efficiency ;

= Sum of task times / Actual number of work stations × cycle time

Although the actual number of required workstation is 5 but we cannot assign task E and F due to the theoretical minimum number of workstation. Therefore, additional work station will be required and there are 5 work stations in total.

= 48 ÷ (5 × 12) × 100

= 80%