Define Verification and Validation in Software Testing

Various Definitions for Verification and Validation :

• Validation checks that the product design satisfies or fits the intended use (high-level checking), i.e., the software meets the user requirements. This is done through dynamic testing and other forms of review.

Verification and validation are not the same thing, although they are often confused. Boehm succinctly expressed the difference between them:

• Validation: Are we building the right product?
• Verification: Are we building the product right?

According to the Capability Maturity Model (CMMI-SW v1.1),

• Verification: The process of evaluating software to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. [IEEE-STD-610].

• Validation: The process of evaluating software during or at the end of the development process to determine whether it satisfies specified requirements. [IEEE-STD-610]

In other words,

• Validation ensures that the product actually meets the user's needs, and that the specifications were correct in the first place, while verification is ensuring that the product has been built according to the requirements and design specifications.
• Validation ensures that "you built the right thing". Verification ensures that "you built it right".
• Validation confirms that the product, as provided, will fulfill its intended use.

From testing perspective:

• Fault – wrong or missing function in the code.
• Failure – the manifestation of a fault during execution.
• Malfunction – according to its specification the system does not meet its specified functionality.

Within the modeling and simulation community, the definitions of validation, verification and accreditation are similar:

• Validation is the process of determining the degree to which a model, simulation, or federation of models and simulations, and their associated data are accurate representations of the real world from the perspective of the intended use(s). Accreditation is the formal certification that a model or simulation is acceptable to be used for a specific purpose.

• Verification is the process of determining that a computer model, simulation, or federation of models and simulations implementations and their associated data accurately represents the developer's conceptual description and specifications.