Editing V-model (section)

== Validation vs. verification ==
{{Main|Verification and validation|Validation (drug manufacture)}}

It is sometimes said that validation can be expressed by the query "Are you building the right thing?" and verification by "Are you building it right?" In practice, the usage of these terms varies.

[[A Guide to the Project Management Body of Knowledge|The PMBOK guide]], also adopted by the [[IEEE]] as a standard (jointly maintained by INCOSE, the Systems engineering Research Council SERC, and IEEE Computer Society) defines them as follows in its 4th edition:<ref name="pmboked4">{{cite book | date = June 2011 | url = https://ieeexplore.ieee.org/document/5937011 | access-date = May 25, 2021 | doi = 10.1109/IEEESTD.2011.6086685 | page=452 | isbn = 978-0-7381-6817-3 | title = IEEE Guide--Adoption of the Project Management Institute (PMI(R)) Standard a Guide to the Project Management Body of Knowledge (PMBOK(R) Guide)--Fourth Edition }}</ref>
* "'''Validation.''' The assurance that a product, service, or system meets the needs of the customer and other identified stakeholders. It often involves acceptance and suitability with external customers. Contrast with ''verification''."
* "'''Verification'''. The evaluation of whether or not a product, service, or system complies with a regulation, requirement, specification, or imposed condition. It is often an internal process. Contrast with ''validation''."