An assembly line is to be designed to operate 7 1/2 hours per day and supply a steady demand of 300 units per day. Here are the tasks and their performance times:

PRECEDING Performance Preceding Performance
TASK TASKS Time (Sec) Task Tasks Time (Sec)
a - 70 g d 60
b - 40 h e 50
c - 45 i f 15
d a 10 j g 25
e b 30 k h, i 20
f c 20 l j, k 25

a. Draw the precedence diagram.

b. What is the workstation cycle time?

c. What is the theoretical minimum number of workstations?

d. Assign tasks to workstations using the longest operating time.

e. What is the efficiency of your line balance?

f. Suppose demand increases by 10 percent. How would you react to this? Assume that you can operate only 7 1_2 hours per day.