How to Measure Line Performance When You Don't Know Product SMV?

I am writing this article to reply to the question asked by Rakesh (name changed).

He wants to calculate his line efficiency but he doesn't have all parameters that are required to calculate line efficiency. He has information on daily production, daily shift hours and a number of operators but don't have garment SMV. He wrote:

Please help me to find the efficiency of a line from the following details.
  • Daily Production: 2000 pieces,
  • Working Hours: 10 Hours,
  • No of machines (Operators): 50 and 
  • SMV - unknown 

To calculate line efficiency normally we use standard formula and find the efficiency figure. The standard formula used to calculate efficiency of a line is as following

Line Efficiency % = (Garment produced by a line* Garment SMV * 100)/ (No. of operators * working hours * 60)

But as Rakesh doesn't have SMV of the product he was making, he can’t calculate the efficiency of his line using above formula. Without having garment SMV you can't determine line efficiency.

In this situation factories, who are in similar situation can measure line performance by Machine Productivity or labor productivity per shift, instead of efficiency. Machine productivity means how many pieces of garments are made per machine in defined hours in a day.

By using productivity figures you can compare your performance with national and international productivity benchmark information for specific products.

For internal use of a factory, like product costing, product to product cost comparison and labor cost justification, productivity data is equally acceptable.

Formula used for productivity calculation

Machine productivity per day= (Daily production quantity /No. of machines)

From the above information, machine productivity of Rakesh’s line is

Productivity per machine (operator) per 10 hours shift = (2000 /50) = 40 pieces

For further details of productivity calculation read our previous article How to calculate labor productivity? 

Second Thought:

In case you still want to express your line performance in efficiency without having product SMV, you can use following formula

Efficiency = (Daily Produced garments X 100 / Daily Target quantity)

This is not a scientific way for efficiency calculation but some factories, those who do not have SMV of their products, practice this calculation method. The daily target is calculated based on past data.

Example: Suppose daily production target for 10 hours shift 3000 pieces, and actual output is 2000 piece. Then line efficiency will be = (2000 * 100/ 3000)% = 66.66%

Please note: I don’t suggest anyone to practice the second method for the calculation of line efficiency. It is explained just for your information. Always use scientific method (Formula#1) to calculate efficiency.

Now SMV calculation is not a difficult job. You can even measure estimated SMV of your products by following methods explained in How to calculate SAM or SMV of a garment. Once you have SMV or SAM of your product calculate your line efficiency by using formula. 

Now I want to listen to your thought. Please post your comments.

Prasanta Sarkar

Prasanta Sarkar is a textile engineer and a postgraduate in fashion technology from NIFT, New Delhi, India. He has authored 6 books in the field of garment manufacturing technology, garment business setup, and industrial engineering. He loves writing how-to guide articles in the fashion industry niche. He has been working in the apparel manufacturing industry since 2006. He has visited garment factories in many countries and implemented process improvement projects in numerous garment units in different continents including Asia, Europe, and South Africa. He is the founder and editor of the Online Clothing Study Blog.

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