Differences between Verification and Validation

Verification and Validation is the process of investigating whether a software system satisfies specifications and standards and fulfills the required purpose. Verification and Validation both play an important role in developing good software development. Verification helps in examining whether the product is built right according to requirements, while validation helps in examining whether the right product is built to meet user needs. In this article, we will learn the difference between Verification and Validation.

Prerequisite – Verification and Validation

What is Verification?

Verification is the process of checking that software achieves its goal without any bugs. It is the process to ensure whether the product that is developed is right or not. It verifies whether the developed product fulfills the requirements that we have. Verification is static testing. 
Verification means Are we building the product right?

What is Validation?

Validation is the process of checking whether the software product is up to the mark or in other words product has high-level requirements. It is the process of checking the validation of the product i.e. it checks what we are developing is the right product. It is validation of the actual and expected products. Validation is dynamic testing. 
Validation means Are we building the right product?

Differences between Verification and Validation

	Verification	Validation
Definition	Verification refers to the set of activities that ensure software correctly implements the specific function	Validation refers to the set of activities that ensure that the software that has been built is traceable to customer requirements.
Focus	It includes checking documents, designs, codes, and programs.	It includes testing and validating the actual product.
Type of Testing	Verification is the static testing.	Validation is dynamic testing.
Execution	It does not include the execution of the code.	It includes the execution of the code.
Methods Used	Methods used in verification are reviews, walkthroughs, inspections and desk-checking.	Methods used in validation are Black Box Testing, White Box Testing and non-functional testing.
Purpose	It checks whether the software conforms to specifications or not.	It checks whether the software meets the requirements and expectations of a customer or not.
Bug	It can find the bugs in the early stage of the development.	It can only find the bugs that could not be found by the verification process.
Goal	The goal of verification is application and software architecture and specification.	The goal of validation is an actual product.
Responsibility	Quality assurance team does verification.	Validation is executed on software code with the help of testing team.
Timing	It comes before validation.	It comes after verification.
Human or Computer	It consists of checking of documents/files and is performed by human.	It consists of execution of program and is performed by computer.
Lifecycle	After a valid and complete specification the verification starts.	Validation begins as soon as project starts.
Error Focus	Verification is for prevention of errors.	Validation is for detection of errors.
Another Terminology	Verification is also termed as white box testing or static testing as work product goes through reviews.	Validation can be termed as black box testing or dynamic testing as work product is executed.
Performance	Verification finds about 50 to 60% of the defects.	Validation finds about 20 to 30% of the defects.
Stability	Verification is based on the opinion of reviewer and may change from person to person.	Validation is based on the fact and is often stable.

Frequently Asked Questions (FAQs) on Verification vs Validation

What is verification and validation also known as?

Verification is also known as static testing. Validation is also known as dynamic testing.

Which is done first verification or validation?

Verification comes before validation. Validation comes after verification.

What is more important validation or verification?

Both are equally important verification ensures correctness, while validation ensures utility and satisfaction of user needs.

Why validation is more difficult than verification?

The complexity of understanding and addressing user needs, the subjectivity of requirements, and the challenges associated with real-world testing make validation a more intricate and demanding process compared to the more straightforward nature of verification.