Verification and Validatation

Verification - checks that the work-product meets the requirements set out for it. 

 An example of this would be to ensure that a website being built follows the guidelines for making websites usable by as many people as possible. Verification helps to ensure that we are building the product in the right way.

Validation - changes the focus of work-product evaluation to evaluation against user needs. This means ensuring that the behavior of the work-product matches the customer needs as defined for the project. 

For example, for the same website above, the guidelines may have been written with people familiar with websites in mind. It may be that this website is also intended for novice users. Validation would include these users checking that they too can use the website easily. Validation helps to ensure that we are building the right product as far as the users are concerned. 

 

Difference between Verification and Validation with Example – Tabular Form

Verification	Validation
1. Verification is a static practice of verifying documents, design and code/program.	1. Validation is a dynamic mechanism of validating / testing the actual product.
2. It does not involve executing the code.	2. It always involves executing the code.
3. It is human based checking of documents / files.	3. It is computer based execution of program.
4. Target is requirements specification, application and software architecture, high level, complete design, and database design etc.	4. Target is actual product-a unit, a module, a bent of integrated modules, and effective final product.
5. Verification uses methods like inspections/review, walkthroughs, and Desk-checking etc.	5. Validation uses methods like black box (functional)  testing, gray box testing, and white box (structural) testing etc.
6. Verification is done by development team to provide that the software is as per the specifications in the SRS document.	6. Validation is carried out with the involvement of client.
7. It can catch errors that validation cannot catch. It is low level exercise.	7. It can catch errors that verification cannot catch. It is High Level Exercise.
8. Verification is to check whether the software conforms to specifications.	8. Validation is to check whether software meets the customer expectations.
9. It, generally, comes first-done before validation.	9. It generally follows after verification.

Verification and validation are explained below:-

Suppose we have the specification related to the project then the first step would be to verify all the documentation related to the specification, whether they are proper or not. This is carried out before the actual software is ready.This process is called Verification.

Now, once we have completed the verification process, the software goes into development phase. After development we have the software and we carry out testing to check whether the requirements in the specification have been built or not. This method id called Validation.

Techniques/Methods of Verification

1. Walkthrough

2. Inspection

3. Review

Techniques/Methods of Validation

1. Testing

2. End Users