verification vs validation

Verification asks whether specified performance requirements are achieved in the laboratory's circumstances. Validation asks whether a procedure is fit for its intended use and establishes the supporting performance evidence. The activities overlap in the measurements they may use, but differ in the question being answered and the extent of evidence required. Neither term means simply checking that an instrument turns on.

For an unchanged, previously validated commercial procedure, local verification is commonly appropriate. A laboratory-developed procedure or a change outside the validated application can require validation. Classify the situation by intended use and technical impact rather than by whether the procedure is called new. A change in specimen type, preparation, reporting range, or clinical application deserves an explicit review of the evidence needed before implementation.

Accreditation assessors expect the laboratory to justify its approach and demonstrate sufficient evidence for the service offered. Confusing the terms can lead either to unnecessary studies or to important performance gaps. Document the decision, study scope, acceptance criteria, and authorization, with a clear assessment of whether later changes alter the original basis for approval.