Cyclone Appliances has developed a new European-style convection oven that will be made on an assembly line. The schedule requires 80 ovens in an 8-hour day. The assembly includes seven tasks

The table below indicates the performance time and the sequence requirements for each task.

Task Performance Time (minutes) Task must follow Task listed below
A 1
B 2 A
C 3 B
D 2 B
E 4 C, D
F 1 E
G 2 F

(a) What is the cycle time for this assembly operation?
(b) What is the theoretical minimum number of workstations?
(c) Draw the precedence diagram.

(a) The cycle time is 480 minutes per day/80 ovens = 6 minutes/oven.
(b) The theoretical minimum number of workstations is the sum of all task times, 15 minutes, divided by the cycle time, 6 minutes; 15/6 = 2.5 or 3 workstations.
(c) The precedence diagram appears below.