Monday, April 18, 2016

How to Calculate SAM of a Garment?


SAM or Standard Allowed Minute is used to measure task or work content of a garment. For the estimation of cost of making a garment SAM value plays a very important role.

General Sewing Data (GSD) has defined set of codes for motion data for SAM calculation. There is also  other methods through which one can calculate SAM of a garment without using synthetic data or GSD. 


Method #1: Calculation of SAM Using Synthetic Data

In this method 'Predetermined Time Standard' (PTS) code are used to establish 'Standard Time' of a garment or other sewing products. 

Step 1: Select one operation for which you want to calculate SAM.

Step 2: Study the motions of that operation. Stand by side of an operator (experienced one) and see the operator how he is doing it. Note all movement used by the operator in doing one complete cycle of work. See carefully again and recheck your note if all movement/motion are captured and correct. (for example motions are like - pick up parts one hand or two hand, align part on table or machine foot, realign plies, etc.)

Step 3: List down all motion sequentially. Refer the synthetic data for TMU (Time measuring unit) values. For synthetic data you can refer GSD (without licence use of GSD code prohibited but for personal use and study one can refer GSD code and TMU values) or Sewing Performance Data table (SPD). Now you got TMU value for one operation (for example say it is 400 TMU). Convert total TMU into minutes (1 TMU=0.0006 minute). This is called as Basic Time in minutes. In this example it is 0.24 minutes.

Step 4: Standard allowed minutes (SAM) = (Basic minute + Bundle allowances + machine and personal allowances). Add bundle allowances (10%) and machine and personal allowances (20%) to basic time. Now you got Standard Minute value (SMV) or SAM. SAM= (0.24+0.024+0.048) = 0.31 minutes.
I like to refer you an article Secret Behind Calculation of Machine Time in SAM for better understand of SAM calculation. 


Method #2: Calculation of SAM Through Time Study


Step 1: Select one operation for which you want to calculate SAM.

Step 2: Take one stop watch. Stand by side of the operator. Capture cycle time for that operation. (cycle time – total time taken to do all works needed to complete one operation, i.e. time from pick up part of first piece to next pick up of the next piece). Do time study for consecutive five cycles. Discard if found abnormal time in any cycle. Calculate average of the 5 cycles. Time you got from time study is called cycle time. To convert this cycle time into basic time you have to multiply cycle time with operator performance rating. [Basic Time = Cycle Time X performance Rating]

Step 3: Performance rating. Now you have to rate the operator at what performance level he was doing the job seeing his movement and work speed. Suppose that operator performance rating is 80%. Suppose cycle time is 0.60 minutes. Basic time = (0.60 X 80%) = 0.48 minutes

Step 4: Standard allowed minutes (SAM) = (Basic minute + Bundle allowances + machine and personal allowances). Add bundle allowances (10%) and machine and personal allowances (20%) to basic time. Now you got Standard Minute value (SMV) or SAM. SAM= (0.48+0.048+0.096) = 0.624 minutes.

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