Problem 6-16 The desired daily output for an assembly line is 360 units. This as
ID: 326865 • Letter: P
Question
Problem 6-16 The desired daily output for an assembly line is 360 units. This assembly line will opcrate 450 minutes per day. The following table contains infomation on this products task times and precedence relationships: TASK TIME (SFCONDS) IMMEDIATE PRFDFCESSOR TASK 35 15 65 E, F D, G Mi b. What is the required workstation cycle time to meet the desired outout rate? Workstation cycle time c. Balance this " e usic the argest number of tolowing tasks. Use the longest task seconds per unit rne as a secr dar cnteno. Leave no cells blank-be certain to enter o wherever required. Work Station Task Idic Time Click to select) v (Click to select) (Click to select) (Click to select) T d. What is the efficiency of your line balance, assuming it is running at the cycle time determined in part b? (Round your answer to 1 decimal place.) Efficiency 91.67 %Explanation / Answer
The precedence diagram of tasks as follows :
A
B
C
D
E
F
G
H
The required cycle time = 450 minutes per day / 360 units per day = 1.25 minutes/ unit = 75 seconds / unit
WORKSTATION CYCLE TIME = 75 SECONDS/ UNIT
Total duration of all tasks = 30 + 35 + 30 + 35 + 15 + 65 + 40 + 25 seconds = 275 seconds
Therefore , minimum number of workstations = 275 seconds/ cycle time = 275 / 75 = 3.66 ( 4 rounded to nearest whole number )
Tasks against workstations basis largest number of following tasks are allocated in a such a way so that total duration of all tasks against a particular workstation shall not exceed the cycle time of 75 seconds
Accordingly , allocation of tasks to various workstations as follows :
WORKSTATION
TASKS
TOTAL DURATION ( SECONDS )
I
A, C, E
30 + 30 + 15 = 75
II
B, D
35 + 35 = 70
III
F
65
IV
G,F
65
Efficiency line balance
= Total duration of all tasks / ( Actual number of workstations x Cycle time ) x 100
= 275 / ( 4 x 75 ) x 100
= 275/300 x 100
= 91.67 % ( rounded to 2 decimal places )
A
B
C
D
E
F
G
H