The Basic Block Company needs to produce 4000 boxes of blocks per 40-hour week to meet upcoming holiday demand. The process of making blocks can be broken down into six work elements. The precedence and time requirements for each element are as follows. Draw and label a precedence diagram for the production process. Set up a balanced assembly line and calculate the efficiency of the line.

WORK ELEMENT	PERFORMANCE	PRECEDENCE TIME (MIN)
A	—	0.10
B	A	0.40
C	A	0.50
D	—	0.20
E	C, D	0.60
F	B, E	0.40