The following tasks are to be performed on an assembly line:

The following tasks are to be performed on an assembly line:

TASK	SECONDS	TASKS THAT MUST PRECEDE
A	18	—
B	12	A
C	10	B
D	14	B
E	26	C
F	28	D
G	15	E-F
H	15	G

 

The workday is 8.75 hours long. Demand for completed product is 900 per day.

 

Required:
(a)	Find the cycle time. (Round your answer to 1 decimal place.)

Cycle time

seconds per unit

 

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

Number of workstations

 

(c)	Balance the line using the longest-operating-time rule. (Leave no cells blank - be certain to enter "0" wherever required. Round your answers to 1 decimal place.)

Work station	Task	Idle time
I	A-B
II	D-C
III	F
IV	E
V	G-H

 

(d)	What is the efficiency of the line balanced as in (c)? (Round your answer to 1 decimal place. Omit the "%" sign in your response.)

Efficiency

%

 

(e)	Suppose that demand rose from 900 to 1,000 units per day. What would you do? (Round your answer to the nearest whole number.)

Reduce cycle time to seconds, which may require rebalancing the line.

 

(f)	Suppose that demand rose from 900 to 1,100 units per day. What would you do? (Round your answer to the nearest whole number.)

Reduce cycle time to seconds, which may require rebalancing the line.

Explanation:

(a):

C = production time per day/required output per day

 

C	=	Production Time Per day (in seconds)	=	8.75*(60*60)	=	35 seconds per unit
		Required Output per day		900

(b):

Ni	=	T	=	138	=	3.94 → 4 work stations
		C		35

(c):

Work station	Task	Task time	Idle time
I	A-B	18-12	5
II	D-C	14-10	11
III	F	28	7
IV	E	26	9
V	G-H	15-15	5

Total task time T = 138

(d):

Efficiency	=	T	=	138	=	0.789 or 78.9%
		NaC		5(35)

(e):

Reduce cycle time to 32. New production level is (8.75 hours/day)(3600seconds per hour)/(32 seconds per unit) = 984 units per day. Therefore, they are 1,000 – 984 = 16 units short. Work (16units)(32 seconds per unit) = 512 seconds overtime.

(f):

Reduce cycle time to 29. New production level is (8.75 hours/day)(3,600 seconds per hour)/(29 seconds per unit) = 1,086 units per day.