Question Layout: line-balancing
A company assembles and mails advertising packages for customers on a contract basis. One such contract has just been signed and the company is developing a layout for the assembly line.
These tasks, their predecessor tasks and task times have been identified and estimated, as shown below. The contract specifies that 50,000 mailers must be processed in 5 working days, the company works only one eight hour shift per day, and employees are allowed two 15-minute coffee breaks per shift.
(i) Draw the precedence diagram to illustrate the precedence relationship?
(ii) Compute the cycle time (in minutes) to achieve the desired output rate?
(iii) What is the theoretical minimum number of stations?
(iv) Which work element should be assigned to which work station?
(v) What is the efficiency of the balance?
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TASK
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Tasks that immediately
precede
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Task time (minutes per mailer)
|
|
A
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Inspect materials for quality
|
---
|
0.30
|
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B
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Prepare kits for assembly
|
A
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0.20
|
|
C
|
Assemble & glue envelopes
|
B
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0.15
|
|
D
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Get and fold circular
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B
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0.10
|
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E
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Attach address to envelope
|
C
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0.10
|
|
F
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Place circular in envelope & seal envelope
|
D, E
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0.15
|
|
G
|
Prepare plastic sleeve to fit over envelope
|
F
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0.05
|
|
H
|
Seal package into plastic sleeve
|
G
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0.15
|
|
I
|
Process addressed mailers through postage machine
|
H
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0.15
|
|
J
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Deliver mailers to mail bin
|
I
|
0.05
|