4. Method B and the software production process

The software development process is no longer quite the same as the classic software V-cycle or system U-cycle. Other tasks appear and some disappear. The main tasks are, in order: software specification in natural language (for software), formal specification, formal general design, formal detailed design, coding, integration testing, functional testing. On the left-hand side of the cycle, for each formal stage, we find proofs within the stage itself and proofs between stages. Unit tests are not required; however, integration tests are necessary when integration with hardware begins.