Published on 07/12/2025
Operational Qualification (OQ) in Pharma: How to Test Equipment Performance and Ensure Compliance
Operational Qualification (OQ) is the documented verification that equipment, systems, or instruments operate as intended throughout all anticipated operating ranges. Following Installation Qualification (IQ), OQ is the second phase in the validation lifecycle and ensures that all critical functions and controls are tested under simulated or actual operating conditions.
This comprehensive guide offers QA, QC, validation, and regulatory teams a structured, regulatory-compliant approach to OQ—covering protocol design, test execution, acceptance criteria, and audit-ready documentation aligned with FDA, EMA, and WHO guidelines.
What is Operational Qualification (OQ)?
OQ validates that equipment functions within established limits and performs reliably under defined conditions. While IQ confirms installation, OQ focuses on operational integrity:
- Verifying operational control systems (buttons, PLCs, SCADA)
- Testing alarms, interlocks, temperature controls, flow rates, and safety mechanisms
- Establishing performance across defined ranges
- Ensuring programmable systems behave as expected
OQ is required for all GMP-critical equipment—mixers, HVAC units, autoclaves, lyophilizers, clean-in-place systems, and even computerized systems under 21 CFR Part 11.
Regulatory Expectations for OQ
- FDA Process Validation Guidance (2011): OQ must demonstrate reproducible operation under GMP conditions
- EMA Annex 15: OQ should cover controls, alarms, software, and
When is OQ Required?
- After installation and successful IQ completion
- After significant changes or relocation (Requalification)
- As part of technology transfer or equipment upgrades
- After preventive maintenance if critical parameters were impacted
Components of an OQ Protocol
An OQ protocol is a structured document that defines how to test the operational capability of equipment. Key sections include:
- Protocol Number and Version Control
- Purpose and Scope
- Equipment Description
- Applicable SOPs and Reference Documents
- List of Instruments and Sensors to be Tested
- Functional Test Matrix (parameters, ranges, methods)
- Calibration Verification Steps
- Alarm and Safety Test Plan
- Environmental Condition Checks
- Acceptance Criteria
- Deviation and CAPA Section
- Summary Report Template
Step-by-Step Execution of OQ
1. Verify Calibration Status
- Ensure all measuring instruments are calibrated with valid traceable certificates
- Record serial numbers, calibration dates, next due dates
2. Perform Functional Testing
Each function of the equipment is tested under standard and worst-case conditions:
| Parameter | Set Value | Observed Value | Pass Criteria | Status |
|---|---|---|---|---|
| Temperature | 40°C | 40.1°C | ±1°C | Pass |
| Flow Rate | 10 L/min | 9.9 L/min | ±5% | Pass |
| Speed (RPM) | 300 | 298 | ±2% | Pass |
3. Test Control Systems and Interfaces
- PLC/HMI interface responses
- Touch panel functionality
- Control loop behavior and PID tuning
- Recipe management (if automated)
4. Execute Alarm and Interlock Testing
OQ must verify that safety features are fully functional:
- Simulate high temperature to trigger alarm
- Open door during operation to test interlock
- Power loss and system restart checks
5. Validate Software and Programmable Logic (if applicable)
- Test input/output sequences
- Validate automation logic paths
- Review audit trails and event logs (21 CFR Part 11)
6. Reproducibility Testing
Each test should be repeated at least 3 times to confirm consistency:
- Cycle time for valves opening/closing
- Chiller cooling response time
- Repeatability of filling volumes
Acceptance Criteria in OQ
- All functional parameters fall within predefined limits
- Alarm and interlock systems work as intended
- No unplanned deviations during execution
- Software logic behaves per URS (User Requirement Specification)
- All test results are documented and signed
OQ Documentation and Attachments
- OQ Protocol and Test Records
- Calibration Certificates
- PLC Screenshots or Audit Logs
- Equipment Manuals and SOP References
- Deviation Reports and CAPA Records (if any)
OQ and Change Control
Any equipment upgrade, configuration change, or automation software update must be routed through change control. Based on impact, partial or full requalification (OQ repeat) may be necessary.
Tips for OQ Audit Readiness
- Use ink signatures, not pencil or erasable markers
- Cross out errors with single line and initial
- Ensure every data point has initials and date
- Use only controlled forms with version numbers
- Keep calibration and traceability records attached
Conclusion
Operational Qualification is a critical GMP requirement ensuring equipment performance aligns with process needs and regulatory expectations. With well-structured protocols, repeatable testing, validated controls, and robust documentation, your OQ becomes a key compliance enabler and process assurance tool.
Explore ready-to-use OQ templates and example test scripts at PharmaSOP.in or learn more about the complete qualification lifecycle at PharmaValidation.in.