Operational Qualification (OQ)

Operational Qualification (OQ) is the documented verification that the facilities, systems, and equipment operate as intended throughout all anticipated operating ranges, in accordance with the approved design specifications and manufacturer’s recommendations.

Overview

Operational Qualification (OQ) is the formal, documented verification that facilities, systems, and equipment—as installed or modified—operate consistently within specified parameters across their anticipated operating ranges. It confirms that all functions, controls, alarms, and safety systems perform reliably under expected use conditions.

OQ typically follows a successful Installation Qualification (IQ). However, for integrated or complex systems, Installation and Operational Qualification may be combined (IOQ) when justified by a risk-based rationale and aligned with lifecycle validation principles.

As per EU GMP Annex 15, OQ is an essential step in demonstrating that the system performs as intended and is suitable for its operational role within a validated process.

Objectives of OQ

The key goals of Operational Qualification include:

  • Confirm Functional Performance: Ensure that the system functions correctly throughout its defined operational range.
  • Verify Control Logic and Software: Test automated functions, user interfaces, and programmable logic controllers (PLCs).
  • Assess Safety Systems: Validate the correct operation of interlocks, alarms, shutdowns, and emergency features.
  • Establish Operational Limits: Define upper and lower thresholds for critical process parameters.
  • Generate Objective Evidence: Provide a documented, traceable record demonstrating consistent functionality under normal and stress conditions.
Mountain range with snow patches and rugged terrain under a clear sky, with snow-capped peaks in the distance.

Main Activities

1. Test Plan Development

  • Risk-Based Scope Definition: Identify critical-to-quality attributes (CQAs) and operational controls that could impact product or patient safety.
  • Test Protocol Structure: Develop a detailed OQ protocol defining test objectives, methodology, acceptance criteria, sampling strategy, and data recording requirements.
  • Range Verification: Include testing at minimum, nominal, and maximum operating ranges, simulating real-use scenarios.

2. Operational Testing

  • Normal Use Scenarios: Test the system’s functionality under expected daily use conditions.
  • Stress and Boundary Testing: Challenge the system at its operational limits to ensure it maintains performance and does not drift or fail.
  • System Integration Tests: Validate communication between subsystems (e.g., sensors to SCADA, HMI to PLC).

Typical operational tests include:

  • Control system checks: Functionality of HMIs, PLCs, software logic, and control loops.
  • Alarm and interlock testing: Verification of safety interlocks, alarms, and fail-safe mechanisms.
  • Functional cycle testing: Repetitive cycling to confirm stability and endurance.
  • Software validation: Testing of firmware or application software for functionality and error handling.

3. Critical Parameter Verification

  • Definition of Critical Parameters: Identify parameters that directly affect quality, safety, or performance (e.g., pressure, temperature, flow rate, dwell time).
  • Tolerance Testing: Verify that critical parameters consistently remain within acceptable limits under varied conditions.
  • Control Accuracy & Repeatability: Confirm the system's ability to maintain and repeat critical parameters over multiple cycles.

4. Challenge Testing

  • Worst-Case Simulations: Deliberately operate under extreme conditions to confirm robustness.
  • Alarm Response Verification: Trigger and verify system response to out-of-specification conditions.
  • Power Interruption Tests: Simulate power failures or surges to verify system recovery behavior.

5. Data Collection and Analysis

  • Real-Time Data Recording: Use data loggers, SCADA outputs, or manual recording to collect test results.
  • Statistical Review: Analyze results using statistical methods where applicable (e.g., standard deviation, control charts).
  • Trend Analysis: Review data for performance consistency and detect early signs of instability.

6. Deviation Management

  • Deviation Reporting: Document all deviations, including their nature, cause, and potential impact.
  • Impact Assessment: Assess whether deviations affect qualification validity or critical parameters.
  • Corrective Actions & Re-testing: Define appropriate remediation steps, execute corrective actions, and re-test where necessary.
A flowchart titled 'Operational Qualification' showing steps: Test Strategy development, Operational Testing, Verification of Critical Parameter, Stress testing of equipment, Data evaluation. Each step has icons and descriptions underneath, ending in 'PQ' with icons for testing documentation and performance gauge.

OQ Documentation Requirements

Robust and well-organized documentation is critical to demonstrating a compliant Operational Qualification (OQ) process. Regulatory inspectors will expect a traceable, signed, and reviewable set of records that prove the system operates reliably and consistently across its intended operating range.

1. Operational Qualification Protocol

A comprehensive OQ protocol ensures that the testing strategy is risk-based, reproducible, and aligned with process requirements and regulatory expectations.

  • Scope and Objectives: Define the operational boundaries and functions being verified, ensuring consistency with the system's intended use and the broader validation strategy per EU GMP Annex 15 and ISO 13485.
  • Test Plan and Methodology: Outline the types of tests to be performed, including normal operation, stress testing, alarm functionality, software control, and worst-case scenarios. Clearly assign responsibilities and define tools and sampling strategies.
  • Acceptance Criteria: Establish pass/fail criteria for each test step based on manufacturer specifications, process requirements, or applicable standards (e.g., ISO 14971, GAMP 5).
  • Deviation Handling: Define how deviations are captured, investigated, and closed in compliance with GMP CAPA expectations and ALCOA+ principles for data integrity.

2. Functional and Technical Documentation

OQ relies on a clear understanding of system behaviour and technical specifications. All documentation supporting system functionality should be version-controlled and readily accessible.

  • Functional Specifications: Confirm system functions, sequences, and control strategies, including software and HMI logic.
  • Process Flow Diagrams and Control Logic: Provide schematics and ladder logic diagrams, where applicable, to support control system verification.
  • Alarm and Interlock Matrix: Document expected alarm triggers, interlock actions, and system responses for testing during OQ.

3. Operational Test Records

Test execution must be rigorously documented to ensure traceability, reproducibility, and audit readiness.

  • Test Execution Sheets: Completed records showing operator initials, execution dates, actual readings, and outcome status for each test step.
  • Raw Data and Digital Outputs: Preserve data from SCADA, PLCs, data loggers, or instrument software in original format with version traceability.
  • Control System Verification: Document results of software logic, user access levels, alarm testing, and safety interlock verification in accordance with GAMP 5 and FDA 21 CFR Part 11, if applicable.

4. Calibration and Instrumentation Records

Accuracy of measurement and control must be ensured through traceable calibration and verification of all instruments used during OQ.

  • Calibration Certificates: Maintain valid certificates for all thermocouples, pressure transducers, timers, and other critical measurement devices.
  • Instrument Index: Track calibration status and traceability chain (to ISO/IEC 17025 or national standards) for all test instruments.
  • Verification Logs: Include records confirming calibration status was verified prior to test execution.
A modern wooden house on a grassy hillside with a lake and mountain range in the background during dusk.
Landscape with mountain range in the background, green rolling hills, and a stone patio with steps and ornamental grasses in the foreground.

Make it

Qualification with Confidence

OQ isn’t just about ticking boxes—it’s about ensuring your equipment and systems perform reliably, consistently, and safely within their defined operational ranges.

At SciReg Consulting, we transform regulatory expectations into operational excellence. Whether you're qualifying cleanroom HVAC systems, automated manufacturing lines, or QC instruments, our expertise ensures compliance without compromise.

We deliver:

  • Comprehensive, risk-based OQ protocols aligned with EU GMP Annex 15 and ISO 13485.
  • Hands-on support for test execution, deviation handling, and system challenge scenarios.
  • Clear, audit-ready documentation that withstands scrutiny from regulatory authorities and notified bodies.
  • Seamless integration with your validation lifecycle—from IQ through PQ.

Need to combine IQ and OQ into a seamless IOQ? Require robust software and alarm testing? Or facing complex systems with multiple critical parameters?

SciReg Consulting makes your OQ practical, compliant, and efficient—building confidence in both system performance and regulatory readiness.

Partner with SciReg Consult to build and execute a qualification framework that meets today’s ATMP regulatory requirements—and evolves with tomorrow’s innovations.