As part of a major plant renovation project, the industrial engineering department has been asked to balance a revised assembly operation to achieve an output of 240 units per eight-hour day. Task times and precedence relationships are as follows: Task Duration Immediate
(minutes) Predecessor
a 0.2 -
b 0.4 a
c 0.2 b
d 0.4 -
e 1.2 d
f 1.2 c
g 1.0 e, f
Do each of the following:
A. Determine the minimum cycle time, the maximum cycle time, and the calculated cycle time.
The minimum cycle time minutes
The maximum cycle time minutes
Calculated cycle time minutes
B. Determine the minimum number of stations needed.
C. Assign tasks to workstations on the basis of greatest number of following tasks. Use longest processing time as a tiebreaker. If ties still exist, assume indifference in choice.
Work stations Following Tasks
I (A, B, D, C) ( A, B, C, D) ( D, C, A) ( A ) ( D, B, C)
II (E) ( D, C, A) (C, F, B) (A) (B, E)
III (B) (F) (F, G) (E) (C)
IV (A, B, C) (E, F) (G) (E) (C, D)
D. Compute the percentage of idle time for the assignment in part d. Use the actual bottleneck cycle time in your calculation.