Production Plan Without SAM Value

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How to Make Production Plan Without SAM Value? [Q&A]

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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.

Last week I have posted an article ‘Role of SAM value in Production planning and control’ and this post is based on that question. Yes, there is a way to perform production planning tasks without garment SAM value. In this article I will show you the method.

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
• Order booking  
• Order scheduling
• 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.

SAM in Garment Industry

What is the Meaning of SAM in Garment Industry?

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As defined in the book Introduction to Work Study, ILO,

SAM is the time value arrived at for a task based on the average rate of output which qualified workers will naturally achieve without over exertion provided that they know and adhere to the specified method and provided that they are motivated to apply themselves to their work.

Here SAM stands for Standard Allowed Minute.


In garment industry, specifically in production SAM is used for measuring work. In the factory work study department (also know as Industrial Engineering department) measure and calculate SAM for sewing operation using standard calculation method. Read 'How to calculate SAM of the garment'
SAM is used many ways directly and indirectly. Some of those are

• Factory as well as individual operator performance is measured by means of SAM
• Labor cost and associated cost ratios are measured by SAM 
• Operators payroll and incentive amount is calculated based on earned SAM
• Latest production scheduling systems like line balancing system and performance measuring systems use SAM as one of the primary parameters. 

An organised garment manufacturing company can not think about managing and controlling shop floor without using SAM of the garment and  individual operations. Even apparel buyers do negotiation of garment manufacturing price based on garment SAM. 

To derive most appropriate SAM value of a garment, factories use PTS based systems. Standard Time is also derived from time study method.  

Garment SAM Calculation and Use of Rating Factor

An Interesting Question on Garment SAM Calculation and Use of Rating Factor

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An OCS reader wrote me following mail. Go through it and try to find out how would you explain him to solve his problem.

"I have a question about calculating SAM for an operation or a garment.

If you use the formula

Basic time= Observed time * performance rating and use a higher performance rating the time taken for the operation is higher than if you took a lower performance rating that is lower.

For example. observed time is 10 minutes. with this - if the operator is at 100% performance then the operation's Basic time (SAM value) will be 10 minutes (10X1). But if an operator is at 50% performance (meaning half as efficient as an operator at 100% performance) for with the same average time for an operation then basic time is 5 (10 x 0.5) Is this to mean that a lower operator performance will yield faster completion of garment making tasks? that seems counter intuitive to me. Please explain"

For a while I also started thinking, how it is coming? A higher rated operator taking higher time than the low rated operator. I know it is not true. But where the problem lies in above example? 

I answered him with following explanation.

Don't worry. Just go through following explanation. You will find what is wrong in the above example.

You are going set standard time (SAM) of an operation through time study. First you need to calculate Basic Time. You need to level the observed time (cycle time) to get standard time. And leveling of time is done by multiplying Rating factor (performance rating). 

Formula: Basic time = Observed time X Rating 

(If we do not consider allowances, Basic time=standard time)
Example, You timed one operator and it is 10 minutes, you rate her 50%. As the operator's rating is less than 100%, she would take higher time than the standard time. And standard time would be lower than 10 minutes. Right? 

So you multiply rating with observed time to calculate basic time. And it is (10 * 50%) = 5 minutes. It means an operator who works at normal pace (no too fast or no too slow) should take 5 minute to complete this operation. For same operator, taking 10 minutes to compete that operation and you rate her 100%. Logically, it is not possible. Either you timed wrong or rate her incorrectly.
In reverse way, a 100% operator and a half efficient (50%) operator can not complete a task in same time (10 minutes). Your assumption is wrong in the above example.
Conclusion: A low performance operator would take higher time to complete the given operation than a higher performance operator.