DQ, IQ, OQ, And PQ: Concept, Applications and FAQs

DQ, IQ, OQ, and PQ are foundational pillars of the validation process in regulated environments, ensuring that equipment and systems are designed, installed, operated, and perform according to strict regulatory and operational standards. These are part of Good Manufacturing Practices (GMP) to ensure that equipment, facilities, and processes meet defined standards of quality, safety, and compliance.

Implementing these qualification phases not only demonstrates due diligence and regulatory compliance but also ensures that products are manufactured in a safe, reliable, and reproducible manner. Understanding and executing each phase effectively is essential for maintaining quality systems, protecting patient safety, and supporting successful audits and inspections.

DQ, IQ, OQ, And PQ: Concept Overview

1. Design Qualification (DQ)

• What it is: Verification that the design of facilities, systems, or equipment meets the requirements of the intended purpose.
• Key Elements:
  • User Requirement Specifications (URS)
  • Functional Requirements
  • Regulatory requirements (e.g., FDA, EMA)
• When it’s done: During the project planning or procurement phase.
• Applications:
  • New equipment purchase
  • Facility design
  • Software systems (e.g., LIMS)
• Case Study: DQ must meet the user specification. For example, if the user requires HPLC with a binary gradient system, an isocratic HPLC system will not serve the purpose. The necessary and sufficient condition is that there will be no validation if the system does not satisfy the user’s

2. Installation Qualification (IQ)

• What it is: Verification that equipment has been received and installed according to the manufacturer’s specifications.
• Key Elements:
  • Checklists for parts and manuals
  • Utilities verification (e.g., voltage, air, water)
  • Calibration certificates
• When it’s done: After equipment delivery and setup.
• Applications:
  • Equipment setup
  • Utility connections
  • IT systems

3. Operational Qualification (OQ)

• What it is: Testing to ensure the system or equipment operates as intended under specified conditions.
• Key Elements:
  • Functionality checks (e.g., alarms, interlocks)
  • Range testing (min/max values)
  • Software interface validation
• When it’s done: After IQ, before production.
• Applications:
  • HVAC systems
  • Autoclaves, mixers
  • PLC-controlled systems
• PQ includes preventive maintenance and regular tests, such as a system suitability test. For a computer system, it includes regular data backup, virus checks and change control procedures.

4. Performance Qualification (PQ)

• What it is: Testing to verify the system performs effectively and reproducibly in a production environment.
• Key Elements:
  • Use of actual materials
  • Multiple runs under normal conditions
  • Sampling and testing
• When it’s done: After successful OQ, in real production.
• Applications:
  • Final product runs
  • Cleaning validation
  • Stability chambers

Conclusion

Related:

• Relative Response Factor (RRF) in Pharmaceutical Analysis

FAQs

Further Reading

A Basic Guide to IQ, OQ, PQ in FDA-Regulated Industries