Software validation is to check that the software of product satisfies or fits the intended use (high-level checking. There are two ways to perform software validation: internal and external. During internal software validation it is assumed that the goals of the stakeholders were correctly understood and that they were expressed in the requirement artifacts precisely and comprehensively. If the software meets the requirement specification, it has been internally validated. External validation happens when it is performed by asking the stakeholders if the software meets their needs. Different software development methodologies call for different levels of user and stakeholder involvement and feedback; so, external validation can be a discrete or a continuous event. Successful final external validation occurs when all the stakeholders accept the software product and express that it satisfies their needs. Such final external validation requires the use of an acceptance test which is a dynamic test.

Validation Testing, carried out, to determine if the system complies with the requirements and performs functions for which it is intended and meets the organization’s goals and user needs. This kind of testing is very important, as well as verification testing. Validation is done at the end of the development process and takes place after verification is completed.

Thus, to ensure customer satisfaction, developers apply validation testing. Its goal is to validate and be confident about the product or system and that it fulfils the requirements given by the customer. The acceptance of the software from the end customer is also its part.

When software is tested, the motive is to check the quality regarding the found defects and bugs. When defects and bugs are detected, developers fix them. After that, the software is checked again to make sure no bugs are left. In that way, the software product’s quality scales up.

Stages of Validation testing Process:

Validation Planning – To plan all the activities that need to be included while testing.
Define Requirements – To set goals and define the requirements for testing.
Selecting a Team – To select a skilled and knowledgeable development team (the third party included).
Developing Documents – To develop a user specification document describing the operating conditions.
Estimation/Evaluation – To evaluate the software as per the specifications and submit a validation report.
Fixing bugs or Incorporating Changes – To change the software so as to remove any errors found during evaluation.

Validation Testing Variations:

Component/Unit Testing – The aim of the unit testing is to look for bugs in the software component. At the same time, it also verifies the work of modules and objects which can be tested separately.
Integration testing- This is an important part of the software validation model, where the interaction between the different interfaces of the components is tested. Along with the interaction between the different parts of the system, the interaction of the system with the computer operating system, file system, hardware, and any other software system it might interact with, is also tested.
System testing- System testing is carried out when the entire software system is ready. The main concern of system testing is to verify the system against the specified requirements. While carrying out the tests, the tester is not concerned with the internals of the system but checks if the system behaves as per expectations.
Acceptance testing- During this testing, a tester has to think like the client and test the software with respect to user needs, requirements, business processes and determine whether the software can be handed over to the client or not.
Alpha testing- This type of testing is done at the developers’ site by potential customers/users. Any problems encountered during this testing are rectified by the developers then and there.
Beta testing- Once the software passes the alpha testing stage, beta testing is done at the user’s end.
Regression testing- This testing is done after the desired changes or modifications are made to the existing code. The code, when put to test, may have certain errors that can be resolved by making essential changes. The software is again put to test after these changes are made to check whether the new code fulfils customer requirements or not.
There is a notion as Independent Validation testing – If the validation tests are carried out by a third party, they are known as independent validation and verification (IV&V). The developer needs to provide the user manual to the third party tester. This manual should clearly contain the standard working conditions of the software. These third-party organizations submit a validation report to the developer after the software is tested. The developer, upon receipt of this report, makes the required changes to the software and repeats tests it to check whether the customer needs are met or not.

Software validation testing is an important part of the software development lifecycle (SDLC), apart from verification, debugging, and certification. Validation testing ensures that the software meets the quality standards set by the customer and that the product meets customer requirements.