Performance Qualification of Manual Terminal Crimping Process for Heart-Lung Machine Production
A cardiovascular device manufacturer required documented evidence that their manual terminal crimping process for HLM (Heart-Lung Machine) cable assemblies would consistently produce product within IPC/WHMA-A-620B specifications when operated at nominal conditions across multiple production lots. The challenge involved validating operator-dependent manual crimping across two wire gauges (14 AWG and 24 AWG) with different terminal types and crimp height specifications. Critical concerns included operator variability as the primary process parameter, preventing excessive or insufficient crimping, ensuring crimp form quality, and maintaining dimensional accuracy (crimp height) within tight tolerances (±0.002 inches).
Project Metrics
Tools & Standards
Problem Definition
A cardiovascular device manufacturer required documented evidence that their manual terminal crimping process for HLM (Heart-Lung Machine) cable assemblies would consistently produce product within IPC/WHMA-A-620B specifications when operated at nominal conditions across multiple production lots. The challenge involved validating operator-dependent manual crimping across two wire gauges (14 AWG and 24 AWG) with different terminal types and crimp height specifications. Critical concerns included operator variability as the primary process parameter, preventing excessive or insufficient crimping, ensuring crimp form quality, and maintaining dimensional accuracy (crimp height) within tight tolerances (±0.002 inches).
System Constraints
Engineering Decisions
Selected four operators by Production Supervisor to represent full production staff population
Validated two terminal/wire combinations: 14 AWG (0.063″ ± 0.002″) and 24 AWG (0.040″ ± 0.002″)
Produced 450 total samples: 225 per wire gauge (75 per work order × 3 work orders)
Used manual crimp tools designed to prevent excessive/insufficient crimping (Tyco 91500-1, AMP 90450-2)
Required all operators to be trained and certified to IPC/WHMA-A-620B standards
Tested both visual inspection (crimp form) and mechanical testing (crimp height)
Applied exact binomial confidence interval statistical method for tolerance analysis
Validation Strategy
- 14 Gage Wire: 225/225 samples passed visual inspection (0 failures)
- 14 Gage Wire: 225/225 samples passed crimp height testing (0 failures)
- 24 Gage Wire: 225/225 samples passed visual inspection (0 failures)
- 24 Gage Wire: 225/225 samples passed crimp height testing (0 failures)
- Total: 450/450 samples met IPC/WHMA-A-620B specifications (100% pass rate)
- Statistical claim validated: 94% of all units meet specifications with 99% confidence
- Zero excessive crimps, zero insufficient crimps, zero crimp form defects detected
- All crimp heights within ±0.002″ tolerance across all samples
Risk & Mitigation
Final Outcome
Successfully qualified manual terminal crimping process for HLM production with zero defects across 450 samples spanning six work orders and two wire gauges. Demonstrated that properly trained and IPC-certified operators using designed crimp tools can consistently produce terminals meeting IPC/WHMA-A-620B specifications for both crimp form and crimp height. The validation established process capability with 99% confidence that 94% of all future production units will meet specifications, providing documented evidence for regulatory compliance and production release. The deviation and subsequent re-measurement demonstrated robust quality controls and commitment to data integrity.