In software project management, software testing, and software engineering, verification and
validation is the process of checking that a software system meets specifications and
that it fulfills its intended purpose.
It may also be referred to as software quality control.
It is normally the responsibility of software testers as part of the software development
lifecycle.
Definitions Validation checks that the product design
satisfies or fits the intended use, 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
Validation: Are we building the right product?)
Verification: Are we building the product right?)
According to the Capability Maturity Model, Software 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] Software 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] In other words, software validation ensures
that the product actually meets the user's needs, and that the specifications were correct
in the first place, while software verification is ensuring that the product has been built
according to the requirements and design specifications.
Software validation ensures that "you built the right thing".
Software verification ensures that "you built it right".
Software 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.
Related concepts Both verification and validation are related
to the concepts of quality and of software quality assurance.
By themselves, verification and validation do not guarantee software quality; planning,
traceability, configuration management and other aspects of software engineering are
required.
Within the modeling and simulation community, the definitions of validation, verification
and accreditation are similar: M&S 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 represent
the developer's conceptual description and specifications.
The definition of M&S validation focuses on the accuracy with which the M&S represents
the real-world intended use(s).
Determining the degree of M&S accuracy is required because all M&S are approximations
of reality, and it is usually critical to determine if the degree of approximation is
acceptable for the intended use(s).
This stands in contrast to software validation.
Classification of methods In mission-critical software systems, where
flawless performance is absolutely necessary, formal methods may be used to ensure the correct
operation of a system.
However, often for non-mission-critical software systems, formal methods prove to be very costly
and an alternative method of software V&V must be sought out.
In such cases, syntactic methods are often used.
Test cases
A test case is a tool used in the process.
Test cases may be prepared for software verification and software validation to determine if the
product was built according to the requirements of the user.
Other methods, such as reviews, may be used early in the life cycle to provide for software
validation.
Independent Verification and Validation Software verification and validation often
is carried out by a separate group from the development team.
In such cases, the process is called "independent verification and validation", or simply IV&V.
Regulatory environment Verification and validation must meet the
compliance requirements of law regulated industries, which is often guided by government agencies
or industrial administrative authorities.
For instance, the FDA requires software versions and patches to be validated.
See also
Compiler correctness Cross-validation
Formal verification Functional specification
Independent Verification and Validation Facility International Software Testing Qualifications
Board Software verification
Software requirements specification Validation
Verification and validation – General Verification and Validation of Computer Simulation
Models Notes and references
External links Chapter on Software quality in SWEBOK