Balancing means even distribution of work load. To distribute work load Pitch Time is calculated. Pitch Time is the regular interval at which products come out of an assembly line.
Pitch Time = SAM / Total No of Operators
Piece Flow per Hr = 60/ Pitch Time
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OP NO. |
OPERATION DESCRIPTION |
M/C |
SAM |
MAN POWER |
HOURLY |
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Difference |
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1 |
SHOULDER JOINT (B) |
OL |
0.40 |
1 |
150 |
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-30 |
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2 |
NK RIB MAKE & TURN OUT |
OL |
0.35 |
1 |
171 |
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-9 |
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3 |
NK RIB JOINT AT BODY |
OL |
0.25 |
1 |
240 |
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60 |
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4 |
MRK AT NK LBL JOINT PSN |
H/W |
0.15 |
1 |
400 |
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220 |
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5 |
LABEL JOINT AT NK PSN |
LST |
0.20 |
1 |
300 |
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120 |
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6 |
SLVE JOINT |
OL |
0.45 |
1 |
133 |
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-47 |
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7 |
SLVE CUFF MAKE |
LST |
0.25 |
1 |
240 |
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60 |
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8 |
SLVE CUFF TURN OUT |
H/W |
0.20 |
1 |
300 |
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120 |
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9 |
SLVE CUFF JOINT |
OL |
0.45 |
1 |
133 |
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-47 |
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10 |
BTM MAKE |
OL |
0.25 |
1 |
240 |
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60 |
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11 |
BTM HEM |
OL |
0.55 |
1 |
109 |
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-71 |
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12 |
OUT PUT TRIMING |
H/W |
0.50 |
1 |
120 |
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-60 |
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TOTAL |
4.00 |
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Pitch Time= |
0.33 |
Piece Flow |
180 |
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Even if you load the line based on its capacity, you might find the inventory accumulating due to an unbalanced production. Absenteeism and turnover can greatly affect the line's balance. A change in style and irregular feeding are two other factors that can put a line off-balance. To keep a line balanced you need information on the inventory levels.
While allocating operator to the operation, the skill requirement for that operation should be kept in mind. To help regain balance in an unbalanced situation industrial engineer can use Utility operators, operator transfers and overtime as the last option.
Practically at first we will take the actual cycle time for individual operation of the line. Average of 5 cycle time should be taken in sec & converted into Min.
For Example:
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Operations |
Cycle Time (Sec) |
Avg. |
Time (Min) |
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Op-1 |
32 |
33 |
31 |
32 |
32 |
32 |
0.53 |
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Op-2 |
45 |
47 |
43 |
46 |
44 |
45 |
0.75 |
Now Hourly Capacity of an Operator or Helper for That particular operation will be calculated including 15% allowance.
Hourly Capacity = 60/ Avg. Cycle Time (min) – Allowance%
Find out the Hourly Capacity for every operation. If same operation is done by more than one then the Hourly Capacity for that particular operation will be added together to get capacity.
Make a line graph by using hourly capacity to clearly realize the bottle neck of the line.
To increase the bottle neck capacity take help from higher operation capacity or include man or machine or method study.
By improving line bottle neck we can easily balance the line.