Calculation of SAM

SAM or Standard Allowed Minute is used to measure task or work content of a garment. This term is widely used by industrial engineers and production people in the garment manufacturing industry. For the estimation of cost of making a garment SAM value plays a very important role. In past scientists and apparel technicians did research on how much time to be allowed to do a job when one follows standard method during doing the job. According to the research study minute value has been defined for each movement needed to accomplish a job. Synthetic data is available for each movement.

General Sewing Data (GSD) has defined set of codes for motion data for SAM calculation. There are also other methods through which one can calculate SAM of a garment without using synthetic data or GSD. In this article both methods are explained in the following.

Method #1: Calculation of SAM Using Synthetic Data

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 license 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). Assume 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.

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.

ASCT is average single cycle time and can be calculated by following formula

Step 3: Performance efficiency

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 ASCT is 0.60 minutes so target single cycle time TSCT = (0.60 X 80%) = 0.48 minutes

TSCT is target single cycle time and can be calculated by

TSCT= ASCT*rating or efficiency

Step 4: Standard allowed minutes

SAM = TSCT * (1 + MDA% + PF %) + BHT.

MDA is machine delay allowance

PF is personal fatigue

BHT is bundle handling time (standard)

Suppose bundle allowances (10%) and machine and personal allowances (20%) to TSCT. Now you got Standard Minute value (SMV) or SAM. SAM= 0.624 minutes.

There are two schools of thoughts

·         One say’s SAM and SMV are same

·         Other say SAM and SMV are different