Structured methodology+object-oriented methodology+formal methods: methodology of SOFL

There is a growing disappointment that formal methods have not been widely adopted in industry. One reason for this is that their application consumes prohibitive amounts of resource. Much research on the integration of available formal methods (e.g. Z, VDM, B-Method) and other structured methodology or object-oriented methodology have been conducted in order to make formal methods more practicable but its success has been very limited. However, little effort has been made to integrate properly formal methods, structured methodologies and object-oriented methodologies in order to take advantage of the desirable features of the three approaches. As an approach to the solution of these problems, we propose a language called SOFL (Structured-Object-Oriented-Formal Language) for system development. It supports the concept that a system be constructed using the structured methodology in the early stages of its development, and using object-oriented methodology at later, more detailed, levels. During the complete system development process, formal methods are applied in a manner that demonstrates their practicability. We first present the SOFL methodology (i.e. the methodology which SOFL supports), and then define the language SOFL by giving its abstract syntax together with an informal semantics. An example of developing a training centre system is used to demonstrate the usability of SOFL. Finally, future research on SOFL is briefly discussed.