Textech, a large electronics manufacturer, assembles model AT75 handheld calculators at its Midland, Texas, plant. The assembly tasks that must be performed on each calculator are shown below. The parts used in this assembly line are supplied by materials handling personnel to parts bins used in each task. The assemblies are moved along by belt conveyors between workstations. Textech wants this assembly line to produce 540 calculators per hour. 6 minutes in an hour are spent on maintenance activities.

Task	Description	ImmediatePredecessor	Task Time (Minutes)
A	Place circuit frame on jig	-	0.18
B	Place circuit # 1 into frame	A	0.12
C	Place circuit # 2 into frame	A	0.32
D	Place circuit # 3 into frame	A	0.45
E	Attach circuit to frame	B,C,D	0.51
F	Solder circuit connections to central circuit control	E	0.55
G	Place circuit assembly in calculator inner frame	F	0.38
H	Attach circuit assembly to calculator inner frame	G	0.42
I	Place and attach display to inner frame	H	0.30
J	Place and attach keyboard to inner frame	I	0.18
K	Place and attach top body of calculator to inner frame	J	0.36
L	Place and attach power assembly to inner frame	J	0.42
M	Place and attach bottom body of calculator to inner frame	K,L	0.48
N	Test circuit integrity	M	0.30
O	Place calculator and printed matter in box	N	0.39

a) Draw the precedence diagram.

b) Compute the cycle time in minutes.

c) Compute the minimum number of workstations.

d) Combine the tasks into workstations to minimize the total idle time.

e) Which heuristic did you use and why?

f) What is the utilization of the line balance attained in (d)?