Definition · Plain-language
Qualification (IQ/OQ/PQ)
Qualification is the documented, staged proof that equipment or a system is correctly installed, operates correctly, and performs as intended in use.
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The three stages
Qualification is typically performed in sequence. Installation Qualification (IQ) verifies and documents that equipment and its components are received as specified and installed correctly, with utilities, manuals and calibration in place. Operational Qualification (OQ) demonstrates that the equipment operates as intended throughout its anticipated operating ranges, often challenging upper and lower limits. Performance Qualification (PQ) shows that the equipment performs effectively and reproducibly under conditions that mimic, or are, routine production, using the actual process and often actual materials.
Qualification versus validation
The terms are related but not identical. Qualification generally refers to equipment, utilities and systems — proving a piece of kit is fit for use. Validation refers to processes — proving a manufacturing or analytical process consistently yields a result meeting predetermined specifications. Equipment qualification provides the foundation on which process validation is built: a process cannot be validated with confidence on equipment that has not first been shown to be installed and operating correctly.
Where it fits in the lifecycle
Qualification activities sit within a planned validation lifecycle, usually governed by a validation master plan and individual protocols with predefined acceptance criteria. Often a Design Qualification (DQ) precedes IQ to confirm the design is suitable for intended use. Each stage is executed against an approved protocol, deviations are documented and resolved, and a summary report concludes whether the acceptance criteria were met. The qualified state is then maintained through calibration, maintenance and change control.
Key facts
At a glance
- Definition: staged evidence equipment is installed, operates and performs
- IQ: Installation Qualification — installed correctly
- OQ: Operational Qualification — operates across its range
- PQ: Performance Qualification — performs under real conditions
- Scope: applies to equipment, utilities and systems
- Feeds: provides the basis for process validation
Common misconceptions
What people often get wrong
Often heard: Qualification and validation mean exactly the same thing.
Actually: Qualification generally applies to equipment and systems; validation applies to processes. Equipment qualification supports, but is not the same as, process validation.
Often heard: You can run performance qualification before installation qualification.
Actually: The stages are sequential: IQ confirms correct installation, OQ confirms operation, then PQ confirms performance. Each builds on the one before.
Often heard: Once IQ/OQ/PQ is complete, no further work is needed.
Actually: The qualified state must be maintained through calibration, maintenance and change control, with requalification when significant changes occur.
Going deeper
