Efficiency compares the minutes you produced with the minutes you had available. It is the most common performance number in garment manufacturing.
Line efficiency
Formula: Line efficiency % = (Output pieces × Garment SAM) ÷ (Operators × Working minutes) × 100
Example: 40 operators work 10 hours (600 minutes). The line makes 1,150 pieces of a style with SAM 12.5.
- Produced minutes = 1,150 × 12.5 = 14,375
- Available minutes = 40 × 600 = 24,000
- Line efficiency = 14,375 ÷ 24,000 = 59.9%
Operator efficiency
The same idea for one person:
Formula: Operator efficiency % = (Pieces made × Operation SAM) ÷ Minutes worked × 100
An operator who makes 110 pieces of a 0.50-minute operation in 60 minutes has 110 × 0.50 ÷ 60 = 91.7% efficiency.
Planning targets from efficiency
Turn the formula around to set a target:
Formula: Target per day = Operators × Working minutes × Planned efficiency ÷ SAM
With 40 operators, 600 minutes, 65% planned efficiency and SAM 12.5 → 40 × 600 × 0.65 ÷ 12.5 = 1,248 pieces per day.
What efficiency does not show
- Lost time: power cuts, waiting for work or machine breakdowns reduce efficiency but are not the operators' fault. Record them as non-productive time (NPT) so you can see the real cause.
- Wrong SAM: if SAM is too high, efficiency looks great. Check SAM regularly.
- Quality: a line can reach 80% efficiency and still produce many defects. Always look at efficiency together with DHU.
Tip: Report efficiency by hour, not only by day. A slow first hour after a style change is normal; a slow hour in the afternoon usually has a cause you can fix.
Use the free target and efficiency calculator to check your numbers.