Operation Management Homework

The desired daily output for an assembly line is 475 units. This assembly line will operate 665 minutes per day. The following table contains information on this product’s task times and precedence relationships:

T

A

S

K

TASK

T

I

M

E

(SE

C

ON

D

S)

IMMEDIATE PREDECESSOR

35

—

B

27

36

22

76

F

40

G

42

D, E

H

32

F, G

b.

What is the workstation cycle time?

Cycle time

 seconds  

c.

Balance this line using the largest number of following tasks. Use the longest task time as a secondary criterion. (

L

eave no cells blank – be certain to enter “0” wherever required.)

Workstation

Task

Idle Time

II

III

I

V

d.

What is the efficiency of your line balance? (Round your answer to 2 decimal places.)

  Efficiency

%  

Some tasks and the order in which they must be performed according to their assembly requirements are shown in the following table. These are to be combined into workstations to create an assembly line. The assembly line operates 10.0 hours per day. The output requirement is 1,200 units per day.

PRECEDING
TASKS

TIME
(SECONDS)

19           

11             

2

7           

9             

14             

12           

J

7             

20           

H, I

15             

J, K

10             

a.

  Workstation cycle time

 seconds per unit  

Balance the line using the longest task time based on the 1,200-unit forecast, stating which tasks would be done in each workstation. (Leave no cells blank – be certain to enter “0” wherever required.)

     Task

    Idle Time

VI

For b, What is the efficiency of your line balance? (Round your answer to 2 decimal place.)

 %  

After production was started, Marketing realized that they understated demand and must increase output to 1,3

50

units. What action would you take? Be specific in quantitative terms, if appropriate.(Input all amounts as positive values. Round down “cycle time” value to the next smallest integer and “overtime” to nearest whole number.)

   cycle time to  seconds or work  minutes of overtime.

An assembly line is to be designed to operate 10 hours per day and supply a steady demand of 400 units per day. Here are the tasks and their performance times:

PERFORMANCE
TIME
(SECONDS)

55

60

25

30

45

 seconds/unit  

What is the theoretical minimum number of workstations? (Round your answer to the next whole number.)

  Minimum number of workstations

Assign tasks to workstations using the longest operating time.

e.

What is the efficiency of your line balance? (Round your answer to 1 decimal place.)

f.

Suppose demand increases by 10 percent. How would you react to this? Assume that you can operate only 10.0 hours per day. (Input all amounts as positive values. Round your answers to 2 decimal places.)

   cycle time to  seconds per unit. Another option is to work  minutes overtime.