python

garment-line-efficiency

Sewing line efficiency calculator for garment factories.

Calculates the industry-standard SAM-based efficiency metric, target output, required worker count, and line balance / bottleneck analysis. Built and used in production by Scan ERP.

Install

pip install garment-line-efficiency

Formula

Efficiency % = (Output × SAM) / (Workers × Hours × 60) × 100

Where:

• Output = pieces produced
• SAM = Standard Allowed Minutes per garment (a.k.a. SMV)
• Workers = number of operators on the line
• Hours = working hours

Example: 25 workers × 8 hours = 12,000 available minutes. Produced 200 pieces of a SAM-15 garment = 3,000 minutes earned. Efficiency = 25%.

Usage

from garment_line_efficiency import (
    calculate_efficiency,
    calculate_target_output,
    calculate_required_workers,
    calculate_line_balance,
    classify_efficiency,
)

# Basic efficiency
calculate_efficiency(output=200, sam=15, workers=25, hours=8)
# → 25.0

# Target output for a desired efficiency
calculate_target_output(efficiency=50, sam=15, workers=25, hours=8)
# → 400.0

# Workers needed to hit a target
calculate_required_workers(target_output=500, sam=15, efficiency=60, hours=8)
# → 26.0417

# Line balance / bottleneck
calculate_line_balance([
    {"operation": "Shoulder join", "sam": 0.5},
    {"operation": "Sleeve attach", "sam": 0.8},
    {"operation": "Side seam",     "sam": 0.6},
    {"operation": "Hem",           "sam": 0.4},
])
# → {"bottleneck": "Sleeve attach", "max_sam": 0.8, "avg_sam": 0.575,
#    "balance_ratio": 71.875, "total_sam": 2.3, "operation_count": 4}

# Classify against industry benchmarks
classify_efficiency(50)  # → 'AVERAGE'
classify_efficiency(70)  # → 'EXCELLENT'
classify_efficiency(80)  # → 'WORLD_CLASS'

Industry benchmarks

Efficiency %	Classification
< 35%	BELOW_STANDARD
35–50%	AVERAGE (typical for Bangladesh / India / Nepal)
51–65%	GOOD
66–75%	EXCELLENT
> 75%	WORLD_CLASS

Related

• garment-smv-calculator — SMV / SAM calculation
• garment-piece-rate — piece-rate payment
• garment-dhu-calculator — DHU quality metric
• garment-aql-calculator — ISO 2859-1 AQL sampling

License

MIT © Santosh Rijal / Scan ERP