14. An assembly line must be designed to produce 40 con- tainers per hour. The f

Question

14. An assembly line must be designed to produce 40 con- tainers per hour. The following data in Table 10.18 give the necessary information TABLE 10.18 Task Information for Problem 14 Immediate Predecessor None Task Task Time (sec) 12 35 10 50 F C (a) Draw a precedence diagram (b) Compute the cycle time (in seconds) to achieve (c) What is the theoretical minimum number of (d) Which work element should be assigned to which (e) What are the resulting efficiency and balance the desired output rate stations? workstation? delay percentages?

Explanation / Answer

The Precedence diagram as follows :

                                                              A

                                D

                                   B

                                E

                                    C

                                F

                                                                 G

Desired output is 40 containers per hour

Thus cycle time = Required time / Corresponding output

                            = 60 minutes or 1 hour / 40 containers

                             = 1.5 minute/ container

CYCLE TIME = 1.5 MINUTES /CONTAINER

Total duration of all tasks ( A to G )

= 60 + 12 + 35 + 55 + 10 + 50 + 5

= 227 SECONDS

Required cycle time of each workstation = 1.5 minutes or 90 seconds

Thus. Theoretical minimum number of workstations

= Total duration of all tasks / Required cycle time

= 227 / 90

= 2.52 ( 3 rounded to next higher whole number )

THEORETICAL MINIMUM NUMBER OF WORKSTATION S = 3

The Balanced workstations are being drawn in such a way so that maximum duration of any workstation cannot exceed the target cycle time of 1.5 minutes or 90 seconds.

The arrangement as follows :

Work station number

Tasks

Maximum total duration ( secs)

Idle time = Cycle time – Maximum total duration

1

A, B

60 + 12 = 72

18

2

D, E

55 + 10 = 65

25

3

F

50

40

4

C,G

35 + 5 = 40

50

Thus resulting efficiency

= Total duration of all tasks / Cycle time x Number of workstations x 100

= 227 / ( 4 x 90 ) x 100

= 63.05 %

Balance delay percentage

= Sum of idle time / Cycle time x Number of workstations       x 110

= ( 18 25 +40 +50) / ( 4 x 90) x    100

= 133/360 x 100

= 36.95%

                                                              A

                                D

                                   B

                                E

                                    C

                                F

                                                                 G

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.