Verification and validation

Verification and validation (also abbreviated as V&V) are independent procedures that are used together for checking that a product, service, or system meets requirements and specifications and that it fulfills its intended purpose.^[1] These are critical components of a quality management system such as ISO 9000. The words "verification" and "validation" are sometimes preceded with "independent", indicating that the verification and validation is to be performed by a disinterested third party. "Independent verification and validation" can be abbreviated as "IV&V".

In reality, as quality management terms, the definitions of verification and validation can be inconsistent. Sometimes they are even used interchangeably.^[2][3][4]

However, the PMBOK guide, a standard adopted by the Institute of Electrical and Electronics Engineers (IEEE), defines them as follows in its 4th edition:^[5]

• "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."

Similarly, for a Medical device, the FDA (21 CFR) defines Validation and Verification as procedures that ensures that the device fulfil their intended purpose.

• Validation: Ensuring that the device meets the needs and requirements of its intended users and the intended use environment.
• Verification: Ensuring that the device meets its specified design requirements

ISO 9001:2015 (Quality management systems requirements) makes the following distinction between the two activities, when describing design and development controls:^[6]

• Validation activities are conducted to ensure that the resulting products and services meet the requirements for the specified application or intended use.
• Verification activities are conducted to ensure that the design and development outputs meet the input requirements.

It also notes that verification and validation have distinct purposes but can be conducted separately or in any combination, as is suitable for the products and services of the organization.