Question

An assembly line must be designed to produce 50 packages per hour. The following data gives the necessary information. Task Information for Problem 3 Task Immediate Predecessor Task Time (sec) A None 25 B A 60 C B 35 D B 45 E B 10 F C, D, E 50 a. Draw a precedence diagram. b. Compute the cycle time (in seconds) to achieve the desired output rate. c. What is the theoretical minimum number of stations? d. Which work element should be assigned to which workstation? e. What are the resulting efficiency and balance delay percentages?

Answer 1

Below is the precedence diagram -

b)

Available Time to achieve desired output = 1 hour = 3600 seconds

Desired output = 50 units

Cycle Time = Available Time to achieve desired output/Desired output

Cycle Time = 3600/50 = 72 seconds per unit

c)

Total Task Time = 25+60+35+45+10+50 = 225 seconds

Cycle Time = 72 seconds

Theoretical Minimum Number of Workstation = Total Task Time/Cycle Time

Theoretical Minimum Number of Workstation = 225/72 = 3.125 = 4 workstations

d)

Workstation	Task
1	A,C
2	B,E
3	D
4	F

e)

Efficiency = Total Task Time/(Number of Workstations*Cycle Time)

Efficiency = 225/(4*72) = 78.13%
Balance Delay = 1-78.13% = 21.87%