Question

Wild Widget must set up an assembly line for widgets. Forecasts show that 52 units per hour should be produced. The tasks required, task times, and precedence relationships are as follows:

Task	Time (seconds)	Predecessors
A	10	–
B	33	A
C	23	A
D	24	C,B
E	20	D
F	18	D
G	36	E,F

b. What is the takt time? (Round your answer to the nearest whole number.)

c. What is the theoretical number of workstations? (Round up your answer to the next whole number.)

d. Assign the tasks to the workstations to balance the line using the longest operating time rule.

Workstation	Tasks in Order	Workstation Time (Seconds)	Idle Time (Seconds)
1
2
3

e. What is the efficiency of the balanced line? (Round your answer to 1 decimal place.)

f. If demand decreased to 42 units per hour, what would be the new takt time? (Round your answer to the nearest whole number.)

Answer 1

b. Takt time = Available time / desired demand rate = 3600 seconds per hour / 52 units per hour = 69 seconds

c. Total task time = 10+33+23+24+20+18+36 = 164 seconds

Theoretical need mber of stations = Total task time / takt time = 164/69 = 2.38 ~ 3

d. Assignment of tasks as per longest operating time rule

Workstations	Tasks in order	Workstation time (seconds)	Idle time (seconds)
1	A, B, C	10+33+23 = 66	66-66=0
2	D, E, F	24+20+18 = 62	66-62=4
3	G	36	66-36=30

e. Cycle time of the balanced line = 66 seconds

Lead time = cycle time * number of workstations = 66*3 = 196 seconds

Efficiency of the balanced line = Total task time / Lead time = 164/196 = 0.837 or 83.7 %

f. New takt time = 3600/42 = 86 seconds