Verification and validation are two terms that we often see within management system standards, such as in the design and development section of ISO 9001, however the two are often confused. Both are used as part of the process of checking, verification ensures that the subject meets its requirements or specifications, while validation checks that it is fit for purpose. In the simplest terms, verification could be expressed as ‘are we building it right?’, whereas validation is ‘did we build the right thing?’
Verification is primarily used to check that a product, system, or service meets its design specifications; that the outputs from the process are able to meet the inputs. For example, if there was a legal requirement that your product was required to meet, verification would be checking that the final design, while on paper, meets that need. Verification tends to be done in a theoretical sense, during the design process, and before the product is built or the service is delivered; after all, it would be a fair waste of time and a blow to an organizations reputation to check such things after delivery, only to then uncover a problem that could have been fixed at the beginning. Verification can also be used on an ongoing basis to check that the product or service continues to meet its various requirements, post-delivery. Verification can include the inspection and testing of individual component parts.
Validation tends to be conducted once the product or service has been realised, typically as part of a pilot programme or test batch, and after verification has occurred. Validation checks that the product or service does what it’s meant to; that it meets its users’ requirements. For example, in the context of training, validation is checking that participants know the necessary and expected knowledge during their training. From this example, you can see that sometimes, validation can only be conducted post-delivery – there is no way to know with absolute certainty whether people will learn what they’re meant to until they have undertaken the training.
“… after all, it would be a fair waste of time to check such things after delivery.”
Each of these steps are important in the design process as they serve two separate purposes – verification is a theoretical exercise in ensuring that no requirements are accidentally missed in the design and development phase, while validation is practical in that it tests that the product or service can actually do what it’s meant to.
Used together, verification and validation support one another to ensure that an organisation’s design and development processes result in products and services that not only satisfy all customer and other requirements, but that they also do what it says on the box.
“Validation checks that the product or service does what it’s meant to…”