Standard Allowed Minutes (SAM / SMV) Calculator

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. The operation is timed over many cycles, and the observed cycle time is entered.
2. The observer rating converts that time to a standard pace, which is what makes times from different operators comparable.
3. Bundle, machine and personal allowances are added as a single percentage uplift on the basic time.
4. The result is the standard allowed minutes for one garment at that operation — the unit costing, target setting and line balancing all run on.
5. Capacity figures follow directly from the SAM and the working minutes available.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Rate the same cycle at 110 instead of 90 — the observer judging that the operator was working above standard rather than below it — and the SAM rises from 0.702 to 0.858 minutes. That is a 22% swing in the cost of the operation, decided by one judgement call.

How to use it

1. Work through the input groups in order — Time Study and Allowances. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Standard Allowed Minutes in the dark results panel — that is the headline figure, expressed in min.
4. Check the supporting rows underneath (Basic Time, Pieces per Operator Hour, Pieces per Operator Shift and Standard Time per Piece) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Costing — cost of making is SAM times the minute rate, so the SAM is where a garment price is really decided.
• Line balancing — operations are assigned to workstations so that no station SAM exceeds the takt time.
• Target setting — hourly targets that operators can actually hold come from SAM, not from the best hour ever recorded.
• Capacity planning — total garment SAM divided by available minutes says how many lines an order needs.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• Rate at least twenty cycles across different operators. A SAM built on one fast operator produces a target the line can never hold.
• Every input is bounded to the range normal practice occupies (Observed Cycle Time 0.01 to 60 min, Performance Rating 30 to 150 % and Bundle & Machine Allowance 0 to 40 %, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• ILO Introduction to Work Study — the source of rating, allowances and the standard time definition used here.
• GSD and MTM are predetermined motion time systems that produce a SAM without a stopwatch; use them where operations are not yet running.

Questions people ask