Question

TASKS		Predecessor	Task Time
A	Warm tortilla	-none	20 sec
B	Rice	-A	10 sec
C	Beans	-B	10 sec
D	Meat	-B	10 sec
E	Salsa	-C, D	10 sec
F	Cheese	-E	5 sec
G	Sour Cream	-E	10 sec
H	Lettuce	-E	10 sec
I	Wrap	-F, G, H	15 sec
J	Bag	-I	5 sec
K	Checkout/pay	-J	25 sec

5. Achieving the above cycle time and output, what is the theoretical number of workstations?

6. Assign tasks to workstations:

Answer 1

The minimum cycle time can be equal to the maximum value of time taken by any task. Here, the task K takes 25 sec. which is the longest time. Hence the cycle time can be taken as 25.

Theoretical min. number of WS = Task time / Cycle time = 130/25=6

Assignment

WS	Tasks	Time	Idle time
I	A	20	5
II	B,C	20	5
III	D,E	20	5
IV	F,G,H	25	0
V	I,J	20	5
VI	K	25	0

Idle time per cycle =20 sec.

Efficiency = task time / (cycle time x Number of WS)

= 130/25x6 = 0.8666