Microfix Inc. has been manufacturing peripherals for microcomputers for the past decade. Over the years, Microfix's mainstay has been hard disk drives. Because of a recent slump in sales, Microfix has decided to expand its product line. After much deliberation among executives, engineers, production personnel, and marketing personnel, a decision was made to produce plug-in 256 MB backup systems for Dell laptop computers. Microfix intends to convert its hard disk expertise to plug-in expertise and to become the cost leader for this one type of product for this one series of machines. Microfix has performed a major analysis of machines and backup systems and feels that 1000 units per week is a reasonable sales goal. Current operations use a standard forty-hour week, and the operations vice-president insists that this be maintained for the new product. Developing the steps in producing the plug-in system has been a project in itself. Engineers, production managers, and assembly line workers collaborated to create a precedence graph and table. First, some twenty-five different steps in production were identified. Then, the group set immediate predecessors for each task. At this point, the line workers developed the task times, using known task times for tasks identical to current tasks, estimates for tasks similar to current tasks, and, for some tasks, conjecture. After all of this effort, the following assembly line table was developed.

Task

Time (in minutes)

Immediate Predecessors

A

1.00

None

B

.40

A

C

.45

A

D

1.10

A

E

.36

A

F

.05

None

G

1.32

B

H

.49

C

I

.54

D

J

1.54

E

K

.35

F

L

2

G

M

.30

H, I

N

1.82

I

O

.89

J

P

1.20

L, M

Q

1.30

N, O

R

.62

O

S

1.30

K

T

1.20

P, Q, R

U

1.80

S

V

.30

T

W

.87

U

X

1.20

U

Y

1.90

V, W, X

DISCUSSION QUESTION

1. (5 p.) Determine the cycle time.

2. (10 p.) Determine the theoretical minimum number of workstations.

3. (70 p.) Balance this assembly line using the longest taks time: which tasks should be performed in which workstation and in what sequence?

4. (15 p.) Calculate the efficiency of your solution.