Mass manufacturing in garment industry is growing in very fast pace and at the same time technology and supporting departments are getting in place. But the real fact is - still most of the garment manufacturing companies don’t have industrial engineering set up. It is not only Bangladesh, even in India and other garment exporting countries, there are many companies those are managed without engineers.
The alternative way is calculating machine productivity to estimate line capacity as well as your factory capacity. To measure machine productivity of a line you don’t need any engineer. If one know the procedure and formula of calculating productivity of the production floor, can find machine productivity easily. Later this productivity data would be considered as base of production planning.
Method of calculating Machine productivity:
Machine productivity is defined as number of units produced per machine in a given time period. From the daily production and machine used to produce those garments you can measure machine productivity per day. Formula used to calculated machine productivity of a line
Machine productivity = (Total production of a line in a day / No. of machines in the line) pieces per day per machine
For example, suppose a line of 35 machines has produced 280 pieces per day (8 hours shift day). Machine productivity of the line
= 280/35 pieces per machine per 8 hours day
= 8 pieces per machine per 8 hours day
Finding daily line output data and machine numbers would not be a difficult job to anyone. Just for your information - style to style productivity will vary depending on work content of the style. So, you can prepare a database of the machine productivity for the previously produced styles. You can use historical data while required and update your machine productivity after each style gets over.
How to use productivity data in Production Planning:
To explain this I need to repeat few things that have been explained in earlier article. That I don't like. Using productivity figure you can measure following things those come under production planning functions
Factory capacity Calculation:
Suppose machine productivity of your factory for ladies blouse is 6 pieces per machine per 8 hours shift and you have total 400 machines in your factory. So daily production capacity of your factory for ladies blouse would be equal to 400*6 pieces or 2400 piece per day (8 hours shift).
Factory capacity calculation formula of a given product
Factory capacity (in pieces) = (Machine productivity * No. of running machines in your factory)
Other planning related tasks those can be performed using factory capacity and line capacity figures are as following -
Lead time calculation
Cost per piece
You can also measure line capacity using labor productivity data. But machine number in a factory is more stable than manpower (labor). I would prefer to suggest you to use machine productivity in measuring your factory capacity in term of how many pieces factory can produce in a certain time period.
Would love to hear how you do planning where garment SAM is not measured.