MetaASSO: an approach for quality

MetaASSO is the approach employed to design ASSO, a formal methodology of conceptual database design for the achievement of conflicting quality requirements. The approach starts from the idea of combining flexibility in modifying a database schema with efficiency in applying object-oriented methodologies, two conflicting requirements. This idea is then refined with more concrete proposals increasing quality and resulting into a modular design of ASSO. The paper focuses on the motivations that support the modules, called methodological tools. This permits extending the methodological tools and studying the effects on the other components. The model supported by ASSO is thus extended with application constraints and operations involving general state variables. The extension is designed in order to reduce the consistency proofs of the model. The design of the methodological tools affects the design of support tools for ASSO. Practical results can be achieved designing an ASSO-toolkit, which reuses some of the B-toolkit functionalities and exploits the features of ASSO in order to reduce the proofs.