A company is designing a process layout for a new product. It plans to use this production line eight hours a day to meet project demand of 240 units per day. The tasks necessary to produce this product are as follows:

Task time immediate predecessor

U 30 none

V 30 u

W 6 u

X 12 w

Y 54 x

Z 30 v, y

Assuming you have found a two station solution, what is the idle time per cycle in this system?