How to Perform Process Validation
Prove a manufacturing process reliably makes conforming product — and keeps doing it.
What a how-to is not
A how-to is SPEQ’s practitioner method, not a procedure. It does not replace your own SOP, it is not a validated approach, and the judgement calls in it belong to your quality unit.
Process validation is the lifecycle proof that a manufacturing process consistently yields product meeting its quality attributes. The FDA’s three-stage model — process design, process qualification (PPQ), and continued process verification — replaced the old "three batches and done" mindset. This is how to run it as a lifecycle.
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Stage 1 — design the process on knowledge
Define critical quality attributes (CQAs) and critical process parameters (CPPs) from development data, DoE, and risk assessment. A validated process starts with understanding what drives quality, not with the PPQ runs.
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Establish a control strategy
Define the controls — parameters, in-process checks, specifications — that keep CQAs in range. The control strategy is what you will confirm and then monitor.
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Stage 2 — write the PPQ protocol
Specify the process performance qualification: the conditions, the sampling plan, and the pre-defined acceptance criteria. The number of PPQ batches is risk-based and justified, not automatically three.
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Execute PPQ under commercial conditions
Run the PPQ at commercial scale with heightened sampling and confirm the process meets acceptance criteria with high assurance before routine release.
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Stage 3 — continued process verification
Once commercial, monitor CQAs and CPPs continuously (trending/SPC) to confirm the process stays in control and to detect drift early. This is the stage most firms under-build.
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Feed monitoring back into the lifecycle
Use CPV signals and the product quality review to trigger investigation, CAPA, or revalidation. Process validation is a loop, not a milestone.
- !Treating process validation as a one-time three-batch event and neglecting Stage 3.
- !Running PPQ without the Stage 1 process understanding to justify parameters and acceptance criteria.
- !A CPV programme that collects data but never trends it, so drift goes unseen until a failure.
- !No link from CPV signals back to CAPA or revalidation.
How to Perform Process Validation: frequently asked questions
Common questions on perform process validation.
How many PPQ batches do I need?
There is no fixed number. The FDA’s 2011 guidance makes the number of process performance qualification batches a risk-based, justified decision supported by process understanding and ongoing verification — not an automatic three.
What are the three stages of process validation?
Stage 1 Process Design (build process knowledge and the control strategy), Stage 2 Process Qualification (PPQ — confirm the process is reproducible at scale), and Stage 3 Continued Process Verification (ongoing monitoring to keep the process in control for its commercial life).
How is process validation different from equipment qualification?
Equipment qualification (IQ/OQ/PQ) establishes that the equipment is fit for use; process validation demonstrates that the overall manufacturing process reliably produces conforming product using that qualified equipment. Equipment PQ feeds the broader process-validation lifecycle.
Does the EU use the same three-stage model?
The concepts align. EU GMP Annex 15 and the EMA process-validation guideline embrace lifecycle validation and ongoing process verification, consistent with the FDA’s three-stage approach, though terminology differs.