Verification and Testing

Verification:
In order to verify the functional correctness of a design, one needs to capture the model of the behavior of the design in a formal language or use the design itself. In most commercial software development organizations, there is often no formal specification of the program under development. Formal verification is used routinely by only small pockets of the industrial software community, particularly in the areas of protocol verification and embedded systems. Where verification is practiced, the formal specifications of the system design (derived from the requirements) are compared to the functions that the code actually computes. The goal is to show that the code implements the specifications.

Testing:
Testing is clearly a necessary area for software or hardware validation. Typically, prior to coding the program, design reviews and code inspections are done as part of the static testing effort. Once the code is written, various other static analysis methods based on source code can be applied.

Typically, system testing targets key aspects of the product, such as recovery, security, stress, performance, hardware configurations, software configurations, etc. Testing during production and deployment typically involves some level of customer-acceptance criteria.