IQ/OQ/PQ Workflow

IQ, OQ and PQ are sequential protocols. Each depends on the successful completion of the prior. Skipping the sequence — running OQ before IQ is closed, running PQ before OQ has signed acceptance criteria — is the most common Annex 15 finding in EU inspections and a recurring 483 in FDA inspections. The sequence is not procedural ceremony; each protocol relies on assumptions established by the prior protocol.

1. URS — User Requirements Specification. What the asset must do, defined before purchase.
2. FS / DS — Functional and Design Specifications. How the vendor implements the URS.
3. DQ — Design Qualification. Documented verification that the proposed design is suitable. Required by Annex 15 for new facilities, equipment and systems.
4. FAT / SAT — Factory and Site Acceptance Testing. Pre-installation verification — leverageable into IQ under Annex 15 §3.5.
5. IQ — Installation Qualification. Verifies the asset is installed correctly per specifications.
6. OQ — Operational Qualification. Verifies the asset operates as intended across its specified ranges.
7. PQ — Performance Qualification. Verifies the asset performs reproducibly in its operational environment with the actual process load.
8. Periodic review and re-qualification. Lifecycle activity established at PQ close.

IQ documents that the equipment, utility or computerised system has been installed correctly per the manufacturer's and design specifications. Typical IQ verifications: equipment identification (asset ID, serial number, model, location), utility connections (electrical specification, compressed air, water, gas, drainage), environmental conditions at installation site, calibration certificates for instruments, software version and configuration, manuals and documentation present, spare parts and consumables logged, training of operators initiated.

Leveraging FAT/SAT is the most powerful efficiency lever Annex 15 §3.5 provides. If FAT was executed at the vendor's site under a sponsor-approved protocol, with sponsor witness, the SAT and IQ can reference rather than repeat those tests. The cost saving is substantial — but only if the FAT protocol was sponsor-approved before execution and the test evidence is fully transferred.

OQ documents that the asset operates as intended across the full specified operating range. Where IQ verifies installation, OQ verifies function. Typical OQ verifications: alarms and interlocks trigger at correct thresholds, control loops respond correctly across the operating range, security and access controls function per requirements, audit trail captures the expected events (for computerised systems), user roles and permissions enforce intended access, error-handling and recovery work as specified, calibration is in place and verified at boundary points.

OQ is where worst-case challenge testing happens. Run the equipment at its specified minimum and maximum operating ranges; test alarm responses with simulated failure conditions; verify recovery from power loss, network loss, and intentional error states. The OQ is your evidence that the asset will perform across the conditions the process will actually encounter — not just at its sweet spot.

For computerised systems, OQ is essentially the GAMP 5 verification activities — system configuration testing, function-by-function testing against the FS, role-based access matrix testing, audit-trail testing, electronic-signature testing (for Part 11 / Annex 11 systems). CSA under FDA's 2022 draft guidance lets sponsors apply critical thinking to scope OQ effort to risk — but the underlying coverage expectation does not change.

PQ documents that the asset performs reproducibly in its operational environment with the actual or simulated process load. Where OQ proves the asset can operate across its specified range, PQ proves it does operate consistently under real conditions. PQ runs replicated trials (typically three or more) using actual product (or process simulant), real operators following the approved SOP, the actual operational environment (cleanroom classification, ambient conditions, utilities at production load).

PQ for equipment used in a manufacturing process is typically the bridge to Process Performance Qualification (PPQ) — stage 2 of FDA's three-stage Process Validation lifecycle. The equipment PQ confirms the equipment is fit to participate in PPQ runs; the PPQ then validates the process as a whole. The two are distinct: equipment PQ scope is the equipment; PPQ scope is the process. A PQ that conflates the two is a routine inspection finding.

For computerised systems, PQ in the GAMP 5 sense is the validation that the system performs intended use in the live business process — typically through user acceptance testing executed by the end-user community under realistic operational conditions.

FDA's 2011 Process Validation guidance defines three stages: Stage 1 Process Design (development), Stage 2 Process Qualification (PPQ — process performance qualification), Stage 3 Continued Process Verification (CPV — ongoing). Equipment IQ/OQ/PQ is a prerequisite for PPQ, not a substitute for it. The IQ/OQ/PQ portfolio for every piece of equipment in the process flow must be closed before PPQ runs begin.

ICH Q10 and ICH Q9(R1) integrate qualification into the pharmaceutical quality system. Qualification status is a control-strategy element; loss of qualification status (deviation, failed periodic review, expired calibration) is an event the PQS must capture and resolve before the affected process can run.

Annex 15 §11 and FDA 21 CFR 211.68 / 820.75 require ongoing qualification status. Periodic review of equipment and computerised systems is typically annual; the depth depends on risk classification. Requalification is triggered by significant change (relocation, major upgrade, change of intended use), by extended idle time, or by data signal (recurring deviations, drift in CPV data, OOS results).

Every change to a qualified asset goes through formal change control. The change record assesses impact on IQ/OQ/PQ status, defines the requalification scope (full or partial, what protocols re-execute), documents the V&V evidence and updates the validation status in the VMP. Skipping change-control assessment of a 'minor' change — a firmware update, a sensor replacement, a calibration interval change — is the highest-frequency inspection finding in the qualification space.

• Sequence collapse — OQ executed before IQ formally closed. Annex 15 §3.6 is explicit that each protocol must close before the next begins.
• FAT/SAT leverage without sponsor-approved FAT protocol. The shortcut is only valid if the upstream protocol was approved in advance.
• OQ challenge testing at single operating point instead of full specified range. Inspectors look specifically for worst-case challenge.
• PQ replicates run without process simulant or actual load. Three perfect runs at empty load do not qualify performance under real conditions.
• PQ conflated with PPQ. Equipment PQ scope is the equipment; PPQ scope is the process. Each has its own protocol and acceptance criteria.
• Periodic review missed. Annex 15 §11 expects documented periodic review; an asset whose last documented review is 5 years old has effectively lost qualification status.