Effective Methods for Software Testing, Third Edition

Chapter 10. Step 4: Validation Testing

This step provides the opportunity to evaluate a system in an executable mode. Although the previous verification steps ensure that the system will function as specified, it is not until the software is executed as a system that there is complete assurance it will function properly.

Testing tradeoffs can be made between the various phases of the life cycle. The more verification testing is performed during the requirements, design, and program phases, the less validation testing that needs to be performed. On the other hand, when only minimal verification testing is performed during the early phases, extensive validation testing may be needed during the test phase.

Overview

Although testers primarily use system documentation to conduct verification testing, they use test data and test scripts to conduct validation testing. Validation testing attempts to simulate the system’s operational environment. Validation testing is effective only when the test environment is equivalent to the production environment.

There are two types of validation testing. The first is the test that the developers implemented to software as specified. At a minimum, this is unit testing and integration testing of the units. The second type of testing tests that the developed software system can operate in a production environment. That is, it tests that the system’s various components can be integrated effectively. Although this second type of testing may be conducted by ...