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Line or operator efficiency — SMV, minutes produced and worked.
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SAM Calculator — Standard Allowed Minutes from Operation Breakdown
Calculate SAM (Standard Allowed Minutes) for any garment style by entering each operation's basic time and allowance percentage. Add bundle handling and machine delay allowances to get the final SAM used for production planning, efficiency tracking and costing. No account needed — numbers update as you type.
SAM must come from formal time study — minimum 3 timing observations per operation rated on the BSI 100-point scale. SAM derived from estimates or memory produces inaccurate efficiency targets and misleading costing.
Step By Step
How to Use This Calculator
5 steps
- Enter each sewing operation name and its basic time in minutes from your time study sheet.
- Set the allowance percentage for each operation — typically 15–20% for ILO standard allowances (personal, fatigue, contingency).
- Add bundle and handling allowance (usually 2–5%) for the time spent picking up and laying down bundles.
- Add machine delay allowance (usually 2–4%) for thread changes, needle breaks and minor stoppages.
- The final SAM is calculated automatically. Use it in your efficiency and production target calculators.
Worked Example
Worked example — Basic polo shirt (5 main operations)
Use this sample to sanity-check your inputs and understand what the final result represents.
- 1Collar attach: 1.20 min basic time, 15% allowance → SAM 1.38 min
- 2Sleeve attach (×2): 1.50 min × 2, 15% allowance → SAM 3.45 min
- 3Side seam (×2): 0.80 min × 2, 15% allowance → SAM 1.84 min
- 4Hem: 0.65 min, 15% allowance → SAM 0.75 min
- 5Total operation SAM: 7.42 min + 2% bundle + 3% machine = Final SAM: 7.79 min
Final Result
SAM 7.79 min → hourly output at 100%: 7.7 pcs, daily at 65% efficiency (480 min): 40 pcs/operator.
Methodology
SAM Formula — ILO Work Study Standard
This section explains the calculation logic, assumptions, and source material used to make the result more trustworthy and easier to verify.
Operation SAM = Basic Time × (1 + Allowance%). Final SAM = Sum of all operation SAMs × (1 + Bundle Allowance%) × (1 + Machine Delay%). Basic Time = Observed Time × Performance Rating / 100. Standard allowances (ILO): Personal 5%, Basic Fatigue 4%, Variable Fatigue 1–8% depending on task.
Practical Guidance
How IE teams use SAM accurately
- 1Always re-study SAM when a method change, new machine type or new operator profile is introduced — old SAM from a different operator on a different machine is not valid for the new setup
- 2Verify SAM accuracy by comparing the theoretical target (capacity × efficiency) against actual daily output over 3–5 days at stable efficiency — a persistent gap of more than ±5% suggests the SAM needs re-study
- 3Break complex operations into smaller elements before timing — this makes it easier to identify which specific movement is consuming excess time and where method improvement can reduce SAM
- 4Include thread trimming time in SAM for operations where operators manually trim — automated trimmers change the SAM significantly and must be re-studied after installation
Frequently Asked Questions
What is the difference between SAM and SMV?+
SAM (Standard Allowed Minutes) and SMV (Standard Minute Value) are the same thing — different abbreviations for the same concept. SMV is more commonly used in older British IE literature and some European factories; SAM is the preferred term in North American and South Asian RMG industries including Bangladesh. Both mean: the time in minutes a qualified, trained operator working at normal pace with appropriate allowances should take to complete one unit of work.
What allowance percentage should I use?+
The ILO standard allowance package for sewing operations typically totals 15–18%: Personal needs (5%) + Basic fatigue (4%) + Variable fatigue depending on physical effort (1–8%) + Contingency (1–2%). Machine sewing on flat fabric typically uses 15%. Operations with awkward posture, repetitive gripping or heavy fabric may use 18–20%. Bundle allowance (2–5%) and machine delay allowance (2–4%) are added separately on top of the operation allowances.
How many observations are needed for a valid time study?+
The ILO Work Study manual recommends a minimum of 3–5 observations per element at a stable method and pace, rated on the BSI 100 scale. For operations with high variability (hand sewing, irregular fabric handling), 10–15 observations may be needed to get a reliable mean. The observations should be taken at different times of day to capture natural pace variation. Any observation where the method was different (dropped bundle, wrong thread, machine jam) should be excluded from the calculation.
How does SAM affect the selling price of a garment?+
SAM directly determines the CM (Cut and Make) cost. CM cost = (Factory hourly cost × SAM) ÷ 60 ÷ Line efficiency. A garment with SAM 20 min at a factory with a CM rate of USD 0.25/min would have a CM cost of USD 5.00 at 100% efficiency, or USD 7.69 at 65% efficiency. Every additional minute of SAM adds proportionally to the CM cost. This is why IE teams focus on SAM reduction through method improvement as the most direct way to improve factory competitiveness.