Process validation
Process validation is documented evidence that a manufacturing process, operating within its defined parameters, consistently produces product meeting its predetermined quality attributes — established across a lifecycle rather than in a single exercise.
Process validation is documented evidence that a manufacturing process, operating within its defined parameters, consistently produces product meeting its predetermined quality attributes — established across a lifecycle rather than in a single exercise.
Plain-English explanation, then the primary regulation it comes from.
Understanding process validation
The lifecycle framing replaced the old idea of validation as three batches and a report. It has three stages: process design, where the commercial process is defined from development knowledge; process qualification, where the design is confirmed capable of reproducible commercial manufacture; and continued process verification, where ongoing assurance is maintained during routine production. The third stage is where most of the value sits and where most sites underinvest.
Annex 15 recognises traditional process validation, continuous process verification, and a hybrid of the two. Continuous process verification uses in-line or at-line monitoring against a defined control strategy rather than a fixed number of batches, and suits processes with strong development understanding. The hybrid approach is common in practice, applying different approaches to different unit operations.
The number of batches is not a regulatory constant. Three is a convention, not a requirement; the number should be justified by process variability, criticality and prior knowledge. Sites that default to three without a rationale are answering a question nobody asked while leaving the real one — how much evidence does this process need — unaddressed.
Continued process verification is where validation either stays true or quietly stops being true. Data collected and filed without interpretation is a documentation exercise, not a control. The test is whether trend review has ever changed a decision: if no CPV review has produced an investigation or an action, it is probably not being read.
- Stage 1 — process design
- Commercial process defined from development knowledge; CQAs and CPPs identified.
- Stage 2 — process qualification
- Facility, utilities and equipment qualified; the process confirmed reproducible at commercial scale.
- Stage 3 — continued process verification
- Ongoing monitoring that the process remains in a state of control.
- Three approaches
- Traditional, continuous process verification, or a justified hybrid.
- Batch numbers justified
- Driven by variability, criticality and prior knowledge — not by convention.
- Linked to the PQR
- CPV data feeds the product quality review and management review.
Common failure modes
- Three batches run because three is traditional, with no rationale recorded.
- CPV data collected and filed but never interpreted, so drift is invisible until a result fails.
- Validation performed on a process the site does not actually run, because the real one includes routine adjustments nobody documented.
- CPPs identified in development and never reconciled with the parameters actually controlled in production.
Where this is written down
- European CommissionEudraLex Volume 4 — EU GMP guidelines
Annex 15, section 5 — Process Validation
- EMAEuropean Medicines Agency
EMA guideline on process validation for finished products
- ICHICH Quality guidelines (Q1–Q14)
ICH Q8 (pharmaceutical development) and Q10 (process performance monitoring)
Read next
Validation
ReadQualityOOT — out of trend
ReadTechnicalAnnex 15 — qualification and validation
ReadTechnicalQualification (URS, DQ, IQ, OQ, PQ)
ReadLooking for a definition rather than an explanation? The GMP glossary covers the abbreviations in one line each.
Knowing the requirement is not the same as closing the gap
If you want to know where your site actually stands against this, the readiness score covers seven quality-system domains in twenty questions, and takes about ten minutes.