In the apparel manufacturing, the efficiency formula is used for measuring batch production efficiency and workers’ production efficiency. There are many applications of measuring individual operator efficiency and Line Efficiency. Like to know the operator work performance and skill level in different operations, their efficiency data is use as reference point. For providing performance bonus, it is essential to know operator’s efficiency for the day. Third, to calculate the projected production capacity of a sewing operation, we need to know the efficiency of the operators who will be assigned to that particular operation.
The efficiency is the work output from an operation, divided by work input from the same operation, and expressed as a percentage. In the following sections, efficiency calculation formula is explained with examples.
Efficiency Formula
The general formula for calculating efficiency is:
Efficiency (%) = (Work output /work input) X 100
If you consider work input and output in ‘minute’, the efficiency formula would be like this – the ratio of total standard minutes produced and total minutes spent on the work.
I am working in the apparel manufacturing sector. In a garment manufacturing factory, we calculate line efficiency every day to measure the production line performance. In the apparel production, the following formula is used for calculating efficiency – whether it line efficiency or individual worker’s efficiency.
Formula#1:
Efficiency % = (Total Minutes Produced X 100)/(Total hours worked X 60)
OR
Efficiency % = (Total SAH Produced X 100)/(Total Hours Worked)
In the above formula, 60 is multiplied to convert hours into minutes and 100 is multiplied to express in percentage.
Total Minutes Produced value of a line is equal to the Line Output x Garment SAM
The Total produced minutes is converted into Produced SAH by dividing by 60.
Formual#2:
Operator Efficiency (%) = (Total Production Quantity in a day/ Daily Target Quantity) x 100
In the second formula, instead of calculating produced minutes, we are considering produced garments as output and production targets for the given hours as an input. The production target is calculated from the garment SAM. The below formula is used for calculating the production target.
Production Target per hour (@100 Efficiency) = (60/Operation SAM)
and
Daily Target quantity = (60 / Operation SAM) x Shift Hours
Also Read: How to calculate hourly production target?
In the garment manufacturing sector, production efficiency data is calculated in many forms. Like, Individual employee efficiency for the day, individual efficiency per hour, line efficiency, and factory efficiency.
In all cases, the efficiency calculation formula remains the same. The total minutes produced and total minutes worked need to be calculated based on where the formula is used.
1. Calculate Individual Operator Efficiency
Let’s find the efficiency of a stitching machine operator (individual worker). As mentioned above, it is essential for calculating operators’ efficiency on daily basis.
Example:
Let’s say a sewing operator worked for 8 hours a day and he produced 400 garments in the given operation. The standard time of the operation is 30 seconds (0.5 Minute).
Note that to calculate produced minutes you need to know the standard minute of the job (operation).
Based on the daily production quantity, the sewing operator produced total minutes (400 X 30)/60 = 200 minutes.
He worked for 8 hours which is equal to 480 minutes.
Therefore, based on the efficiency formula, operator’s efficiency is (200/480) x 100 = 41.67 %
2. Calculate Line Efficiency
To calculate line efficiency, you need data data for manpower working in a line, shift time, Production quantity and Garment SAM. If a line produced more than a garment style, you need to collect data for Style wise production and SAM of each style. Then calculate total SAH produced by the Line and Total Hours worked by the operators atteneded in that line.
The line efficiency calculation method is explained in an earlier post. Please refer to this article – How to calculate line efficiency?
Conclusion
For day to day line efficiency calculation, use a proper Excel Template and fill up the production data and Style SAM everyday after the shift. This template will provide you efficiency data of each line in single screen. In Excel template, you can set the efficiency calculation formula. See the example of the Line Efficiency data of a plant.
| Line No. | Style | SAM | Production Qty | Manpower | Worked Hours | Produced Minutes | Available Minutes | Line Efficiency |
| 1 | Sty-21 | 21 | 410 | 30 | 8 | 8610 | 14400 | 60% |
| 2 | Sty-03 | 35 | 300 | 30 | 8 | 10500 | 14400 | 73% |
| 3 | Sty-12 | 25 | 400 | 25 | 8 | 10000 | 12000 | 83% |
| 4 | Sty-32 | 25 | 450 | 27 | 8 | 11250 | 12960 | 87% |
| 5 | Sty-22 | 22 | 600 | 30 | 8 | 13200 | 14400 | 92% |
| 6 | Sty-41 | 18.5 | 700 | 43 | 8 | 12950 | 20640 | 63% |
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