Operation Management Problem Set

Manufacturing Processes

6

a.

B

35

D

35

H A

25 30

E

15

G

40

C

30

F

65

b. c.

C = production time per day/required output per day = (450 minutes/day)/360units per day = 1.25 minutes per unit or 75 seconds per unit

Work station I

Task A C E F B G D H

Task time 30 30 15 65 35 40 35 25

Idle time

0 10

II III

0

IV

15

d.

Efficiency =

275 T = = .917 or 91.7% 4(75) N aC

5

Chapter 4

7.

a.

C = production time per day/required output per day = (7.5 hour per day) (3600 seconds per hour)/1000units per day = 27 seconds per unit

b.

D

12

H

9

K B

15 24

E

18

I

14

A

15

L

10

F C

6 7

J

7

G

11

Work station I

Task A C B E F I D G H J K L

Task time 15 6 24 18 7 14 12 11 9 7 15 10

Idle time 6 3

II III

2

IV

1

V

0

VI

2

c.

Efficiency =

148 T = = .914 or 91.4% 6(27) N aC

d. Reduce cycle time to 25 ((7.5*3600)/1100 = 24.54 seconds), which requires rebalancing the line or work overtime: (100 units) 27 seconds per unit = 2700 seconds or 45 minutes of overtime.

6

Manufacturing Processes

8.

a.

a

70

d

10

g

60

j

25

b

40

e

30

h

50

l k

20 25

c

45

f

20

i

15

b.

C = production time per day/required output per day = (7.5 hour per day) (3600 seconds per hour)/300 units per day = 90 seconds per unit

c. d.

Ni =

T 410 = 4.56 → 5 work stations = C 90

Work station I

Task a d g j c b e h f I k l

Task time 70 10 60 25 45 40 30 50 20 15 20 25

Idle time 10

II

5

III

5

IV

10

V

10

e. Efficiency =

410 T = = .911 or 91.1% 5(90) N aC

7

Chapter 4

f.

Reduce cycle time to 81 seconds per unit. This produces (7.5 hours)(3600 seconds per hour)/81 seconds per units = 333.3 units. Another option is to work 45 minutes overtime (7.5 x 10% = .75 hour or 45 minutes). There are many other options possible that are combinations of these...