Free tools/Production & IE
SMV Calculator (Standard Minute Value)
Calculate SMV (SAM) for a sewing operation from observed cycle time, performance rating and allowance. What SMV means, the time study steps, the formula and an SMV table.
SMV
0.843min
Basic time
0.733min
Pieces per hour at 100%, one operator
71.2pcs
The formula
SMV (min) = observed seconds / 60 x rating / 100 x (1 + allowance / 100). Basic time = observed minutes x rating / 100.
Worked example
Observed cycle time (average): 40 s, Performance rating: 110 %, Allowance (personal, fatigue, delay): 15 %. Result: SMV = 0.843 min; Basic time = 0.733 min; Pieces per hour at 100%, one operator = 71.2 pcs.
What SMV means and how to measure it
SMV (standard minute value) is the time a trained operator needs to complete one operation at standard pace, including allowances. SAM (standard allowed minute) is the same number under its US name. A garment SMV is the sum of its operation SMVs.
Time study steps: break the job into elements, time 10 to 20 cycles with a stopwatch or video, drop cycles with a missed stitch or an interruption, and average the rest. That average is the observed time.
Rating adjusts for the pace you watched. If the operator worked faster than standard you rate above 100% and the basic time goes up; slower than standard and it goes down. Basic time = observed time x rating / 100.
Allowance adds the time no one can sew through: personal needs, fatigue and unavoidable delay such as thread breaks and bundle handling. The 15% default here is a starting value, not a standard; use the allowance your own factory has set. SMV = basic time x (1 + allowance / 100).
SMV table at 15% allowance
| Observed time (s) | SMV at 90% | SMV at 100% | SMV at 110% |
|---|---|---|---|
| 30 | 0.518 | 0.575 | 0.633 |
| 45 | 0.776 | 0.862 | 0.949 |
| 60 | 1.035 | 1.150 | 1.265 |
| 90 | 1.553 | 1.725 | 1.898 |
| 120 | 2.070 | 2.300 | 2.530 |
SMV in minutes for common observed cycle times at ratings of 90%, 100% and 110%, all with 15% allowance, computed with this calculator.
Assumptions
- Observed time is the average of the cycles you timed, after removing obviously abnormal cycles.
- One combined allowance; split it into personal, fatigue and delay in your own study sheet if you need to show the parts.
- Pieces per hour assumes one operator working at 100% of standard with no off-standard time.
Questions
- What is SMV in garments?
- SMV is the standard minute value: the minutes a trained operator needs for one operation, or one whole garment, at standard pace with allowances. A garment SMV is the sum of its operation SMVs.
- How is SMV calculated?
- SMV = observed time in minutes x rating / 100 x (1 + allowance / 100). A 40-second cycle rated 110% with 15% allowance is 0.667 x 1.10 x 1.15 = 0.843 minutes.
- Is SAM the same as SMV?
- Yes. SAM (standard allowed minute) is the US term and SMV (standard minute value) is used in South Asia and Europe. The calculation is the same.
- What is SMV used for?
- Line targets, operator and machine requirements, line efficiency and CM costing all start from SMV. A wrong SMV makes every one of those numbers wrong in the same direction.
Read the guide
In the platform
Intelactory keeps each SMV with the time study it came from, and the same minutes feed line targets and CM costing.