Quality concepts
Verification and validation
Also called: V&V, verification, validation
Verification and validation are the two halves of confirming quality. Verification asks whether the work was built to its stated requirement — the dimension, the detail, the approved submittal. Validation asks the further question of whether the built result performs the function it exists for once it is put to use. Verifying a piping run means confirming it was installed per the drawing; validating it means pressure-testing it and watching it hold. Together they cover both "built right" and "does the right thing."
Why it matters
Verification alone can sign off work that conforms yet does not function — the flashing that matches the detail but still leaks, the assembly that measures right but was never tested under the load it will see. Validation is the step that catches that gap, which is why systems get commissioned and tested, not just visually inspected against the drawings.
Keeping the two straight also keeps records honest. A passed visual inspection is verification; a witnessed pressure test or functional performance test is validation, and closeout usually needs both on the file.
How it shows up on site
Rough-in inspections and dimensional checks do the verification. Pressure tests, flood tests, functional performance tests and commissioning do the validation — run against the acceptance criteria, witnessed where required, and documented as the evidence the system works.
Checklists that put verification and validation to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- Functional performance testA scripted test that drives a system through its operating modes to prove it responds the way the sequence of operations requires.
- Commissioning (Cx)The process of verifying that installed systems actually perform the way the design and the owner's requirements intended.
- Fitness for purposeWhether installed work actually does the job it was put in to do, not just whether it matches the drawing line for line.
- Acceptance criteriaThe stated, measurable conditions installed work has to meet before it can pass — the yardstick an inspection judges against.
- Quality assurance (QA)The planned system of procedures, plans and checkpoints set up before work starts so the right result is built the first time.
- Quality control (QC)The hands-on inspection and testing of installed work against the spec — checking the actual product, not the process that made it.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.