Benefits Intellectual control of the process, increased quality of the product, and lower life cycle costs are the key benefits of correctness verification. Cleanroom verification motivates tremendous determination by developers that the code they deliver for independent testing be error-free on first execution. Verification is a form of peer review in which each person assumes responsibility for and derives a sense of ownership in the evolving product. Every person in a verification session must agree that the work is correct before it is accepted. Successes are ultimately team successes, and failures are team failures.
Verification is more cost-effective than unit testing for several reasons.
Design errors are identified sooner and as a result are less costly to fix. The expense of building test drivers and test cases for unit testing is eliminated. And the errors remaining after verification are generally easy to find in certification testing and simple to fix. Practice A Cleanroom team applies a set of correctness questions during functional verification. Correctness is established by group consensus if it is obvious to all that the work is correct, and by formal proof techniques if it is not.