Sewing-line efficiency improvement

Learning objectives

• Calculate sewing-line efficiency correctly and honestly.
• Separate operator, method and machine causes of low efficiency.
• Design a short intervention that raises efficiency without hurting quality.

The efficiency equation

Sewing-line efficiency = (Standard minutes produced ÷ Total minutes worked) × 100. Standard minutes come from the operation bulletin. Total minutes worked include every operator on the line for the same clock period.

What efficiency does not tell you

• It does not distinguish poor method from poor operator skill.
• It hides quality problems if reworked pieces are counted as output.
• It reacts slowly to bottleneck moves within the line.

Garment-factory example

A polo line produces 800 shirts at an SMV of 12.5 minutes with 30 operators working 480 minutes. Standard minutes produced = 800 × 12.5 = 10,000. Total worked = 30 × 480 = 14,400. Efficiency = 10,000 ÷ 14,400 = 69.4%. A 3-week intervention that adds a sleeve-attach folder and rebalances two operations raises efficiency to 78% while DHU drops from 12 to 7.

Method

1. Confirm the SMV before quoting efficiency; a wrong SMV wrecks the ratio.
2. Report efficiency together with DHU so quality cannot silently drop.
3. Time only the current bottleneck for the fastest gain.

Common mistakes

• Counting reworked pieces in the output.
• Chasing 100% efficiency and letting quality slip.