Formal methods have yet to achieve wide industrial acceptance for several reasons. They are not well integrated into established industrial software processes, their application requires significant abstraction and mathematical skills, and existing tools do not satisfactorily support the entire formal software development process. We have proposed a language called SOFL (Structured-Object-based-formal Language) and a SOFL methodology for system development that attempts to address these problems using an integration of formal methods, structured methods and object oriented methodology. Construction of a system uses structured methods in requirements analysis and specifications, and an object based methodology during design and implementation stages, with formal methods applied throughout the development in a manner that best suits their capabilities. The paper describes the SOFL methodology, which introduces some substantial changes from current formal methods practice. A comprehensive, practical case study of an actual industrial Residential Suites Management System illustrates how SOFL is used.

This paper discusses the improvement of conventional software reliability growth models by elimination of the unreasonable assumption that errors or faults in a program can be perfectly removed when they are detected.The results show that exponential-type software reliability growth models that deal with errorcounting data could be used even if the perfect debugging assumption were not held, in which case the interpretation of the model parameters should be changed.An analysis of real project data is presented. I. INTRODUCTlON