21. The software design system according to claim 16 , wherein the verified implementation specification generator is arranged to carry out a box structure development method for creating formal implementation specifications.
21. The software design system according to claim 16 , wherein the verified implementation specification generator is arranged to carry out a box structure development method for creating formal implementation specifications. 25. The software design system according to claim 21 , wherein the implementation specification generator comprises a model verifier for analysing the mathematical models representing the run-time implementation behavior to determine if the mathematical models representing the run-time implementation behavior have the required run-time implementation behavior and the model verifier of the implementation specification generator comprises an FDR model checker for checking mathematical models described in CSP notation.