GMP Equipment Qualification (DQ/IQ/OQ/PQ) Explained

DQ, IQ, OQ, PQ appear on almost every GMP audit checklist, yet the four terms are frequently confused even by experienced quality staff. Here is what each stage actually verifies, in the order they happen.

DQ: Design Qualification

Confirms that the equipment you are about to buy or install is actually designed to meet your process requirements, before it arrives on site. Done at the specification and purchasing stage.

IQ: Installation Qualification

Verifies the equipment was installed correctly: utilities connected, calibration certificates on file, documentation complete, and the installed unit matches its approved specification.

OQ: Operational Qualification

Tests that the equipment operates correctly across its full intended operating range, not just at one setting. For an autoclave, this means proving temperature and pressure hold correctly across the range you will actually use.

PQ: Performance Qualification

Confirms the equipment performs consistently under real production conditions, with real or representative load, over repeated cycles. This is the stage that proves the process is reproducible, not just theoretically capable.

Why the Order Matters

Skipping a stage, or running PQ before OQ is complete, is one of the most common findings DGDA and WHO-GMP auditors raise. Each stage builds evidence for the next, and documentation has to show that order clearly.

Our pharmaceutical validation service covers full DQ/IQ/OQ/PQ documentation for autoclaves, ovens, LAF units and cold chambers, formatted the way DGDA and WHO-GMP auditors expect to read it.