Pasteur Pipette Sterilization Oven Upgrade & Validation
The existing sterilization oven system at CooperSurgical was outdated and created multiple operational and compliance risks. The legacy Scanlink software was incompatible with modern Windows OS, hardware was limited to 12 thermocouples versus the required 20 for proper temperature mapping, manual data retrieval required cleanroom entry, and temperature overshoot and oscillation were observed (ranging from 134–140°C when setpoint was 133°C). Oven #4 specifically exceeded setpoint by up to 7°C. These issues created sterility assurance risks, process reliability concerns, regulatory exposure, and operational inefficiency. The business required improved monitoring, control logic, and regulatory compliance while enabling continuous 24/7 operation with remote monitoring capabilities.
Project Metrics
Tools & Standards
Problem Definition
The existing sterilization oven system at CooperSurgical was outdated and created multiple operational and compliance risks. The legacy Scanlink software was incompatible with modern Windows OS, hardware was limited to 12 thermocouples versus the required 20 for proper temperature mapping, manual data retrieval required cleanroom entry, and temperature overshoot and oscillation were observed (ranging from 134–140°C when setpoint was 133°C). Oven #4 specifically exceeded setpoint by up to 7°C. These issues created sterility assurance risks, process reliability concerns, regulatory exposure, and operational inefficiency. The business required improved monitoring, control logic, and regulatory compliance while enabling continuous 24/7 operation with remote monitoring capabilities.
System Constraints
Engineering Decisions
Authored comprehensive User Requirements Specification (URS) defining system requirements
Established 20-thermocouple monitoring architecture (vs. legacy 12-TC system)
Defined alarm architecture with PHL/PLL/fail thresholds and multi-TC decision logic
Implemented 18/20 thermocouples within range requirement with absolute minimum rules
Designed external controller capability to directly drive heaters
Developed temperature mapping strategy: worst-case hot condition, worst-case cold start, shelf-level testing
Optimized thermocouple placement accounting for airflow effects
Established pre-alarm strategy and configurable dwell/alarm behavior
Created structured bench test planning framework (Form ENG-022)
Defined data logging requirements with remote access capabilities
Implemented user access controls and security requirements
Validation Strategy
- Root cause of Oven #4 temperature overshoot identified: faulty main thermocouple
- Systematic troubleshooting performed: reprogrammed controller (issue persisted), replaced controller (issue persisted), replaced main thermocouple (issue resolved)
- Oven calibration verified successful post-repair
- Formal URS established and approved
- FAT (Factory Acceptance Test) framework created
- Temperature mapping plan developed for worst-case validation
- Alarm logic tightened with multi-sensor decision rules
- Improved data logging strategy with ≥30-day retention
- Remote monitoring capability defined
- Reduced cleanroom entry requirements through automated data collection
Risk & Mitigation
Final Outcome
Successfully identified and resolved root cause of temperature control instability in Oven #4, restoring process capability through main thermocouple replacement. Developed comprehensive URS defining upgraded system architecture with 20-thermocouple monitoring, enhanced alarm logic, remote monitoring, and continuous 24/7 operation capability. Established temperature mapping strategy and FAT framework to support validation lifecycle. Improved data logging with ≥30-day retention and reduced cleanroom entry requirements. Created foundation for regulatory-compliant sterilization process with enhanced monitoring, control, and traceability. Project established clear path from legacy 12-TC system to modern 20-TC architecture with Windows 10 compatibility and remote access, addressing sterility assurance, process reliability, regulatory compliance, and operational efficiency requirements.