Line efficiency is the single most important operational metric in a garment factory. It determines your actual cost of making versus your quoted CM, your ability to meet shipment dates, and ultimately your factory's profitability. Yet many factories in Bangladesh track it inconsistently — either using wrong formulas, or only measuring it when something goes wrong. This guide explains the correct calculation and how to use it.
The Efficiency Formula
Line efficiency measures how effectively your workers are converting their available working time into productive output. It compares the theoretical time the work should have taken (based on SMV) against the actual time consumed.
Line Efficiency (%) = (Total Minutes Produced / Total Minutes Available) × 100 Where: Total Minutes Produced = Pieces produced × SMV of the style Total Minutes Available = Total operators × Working hours × 60 Example: 40 operators, 8-hour shift, 480 pieces produced, SMV = 12 minutes Minutes produced = 480 × 12 = 5,760 Minutes available = 40 × 8 × 60 = 19,200 Efficiency = (5,760 / 19,200) × 100 = 30% Note: 30% means something has gone wrong — perhaps first day of a new style.
What Are Realistic Efficiency Targets in Bangladesh?
Efficiency varies considerably by factory tier, style complexity, and where the line is in the learning curve. These benchmarks reflect typical performance across the Bangladesh RMG industry.
Efficiency Benchmarks — Bangladesh RMG Industry
| Factory Category | Typical Efficiency Range | Notes |
|---|---|---|
| Basic CMT factory (non-compliant) | 40 – 55% | High absenteeism, poor layout, no IE department |
| Standard compliant factory | 55 – 68% | Most of Bangladesh's export factories |
| Well-managed lean factory | 68 – 78% | Strong IE team, good line balancing, low turnover |
| Tier-1 / world-class | 78 – 88% | Full lean implementation, low absenteeism, training culture |
| First day of new style (any factory) | 30 – 50% | Normal — learning curve applies |
| Day 5+ (stable production) | Target 65%+ | Should reach standard efficiency by day 5 |
Why Lines Lose Efficiency
The most common causes of low efficiency in Bangladesh factories are: poor line balancing where some operators are idle waiting for work from bottleneck operations; high absenteeism forcing helpers into operator roles they are not fully trained for; frequent style changes without proper pre-production preparation; and machine downtime from poor preventive maintenance.
How to Identify the Bottleneck Operation
The bottleneck is the operation with the highest individual cycle time — it limits the output of the entire line regardless of how fast every other operation runs. Identify it by timing each operation with a stopwatch and comparing against the standard. Any operation exceeding the line's target cycle time (60 / target pieces per hour) is a bottleneck.
Tip
Track efficiency by hour, not just at the end of the shift. An hourly efficiency chart reveals exactly when the line lost time — whether it was at startup (poor feeding), mid-shift (machine breakdown), or after lunch (motivation/energy dip). You cannot fix what you cannot see.