Strategies for Consistency Checking

Viewpoint models of system development are becoming increasingly important. A major requirement for viewpoints modelling is to be able to check that the multiple viewpoint specifications are consistent with one another. The work presented in this report makes a contribution to this task. Our work is particularly influenced by the viewpoints model used in the ISO standardisation architecture for Open Distributed Processing. This report focuses on the issue of strategies for consistency checking. In particular, it considers how global consistency (between any arbitrary number of viewpoints) can be obtained from binary consistency (between two viewpoints). The report documents a number of different classes of consistency checking, from those that are very poorly behaved to those that are very well behaved. The report is intended as a companion to the work presented in [1] and it should be read in association with this document. In particular, the body of this report is a single chapter which should be viewed as additional to the chapters included in [1]. This report contains complete proofs of all relevant results, even though some of the results are obvious and some of the proofs are trivial. A much compressed version of the report is being submitted for publication. Thus, the main value of this report is as a reference document for readers who require a complete presentation of the technical. [1] E. Boiten, H. Bowman, J. Derrick and M. Steen ''Cross Viewpoint Consistency in Open Distributed Processing (Intra Language Consistency)'', Technical Report, Computing Laboratory, University of Kent at Canterbury, report No. 8-95, 1995. Phone: +44 1227 827913, Fax: 44 1227 762811 Email: H.Bowman,E.A.Boiten,J.Derrick,[email protected]

Metamodel-based model conformance and multiview consistency checking

Model-driven development, using languages such as UML and BON, often makes use of multiple diagrams (e.g., class and sequence diagrams) when modeling systems. These diagrams, presenting different views of a system of interest, may be inconsistent. A metamodel provides a unifying framework in which to ensure and check consistency, while at the same time providing the means to distinguish between valid and invalid models, that is, conformance. Two formal specifications of the metamodel for an object-oriented modeling language are presented, and it is shown how to use these specifications for model conformance and multiview consistency checking. Comparisons are made in terms of completeness and the level of automation each provide for checking multiview consistency and model conformance. The lessons learned from applying formal techniques to the problems of metamodeling, model conformance, and multiview consistency checking are summarized

Checking Consistency of Database Constraints

This paper addresses the problem of consistency of a set of integrity constraints itself, independent from any state. It is pointed out that database constraints have not only to be consistent, but in addition to be finitely satisfiable. This stronger property reflects that the constraints have to admit a finite set of (stored as well as derivable) facts. As opposed to consistency, being undecidable, finite satisfiability is semidecidable. For efficiency purposes we investigate methods that check both finite satisfiability as well as unsatisfiability . Two different methods are proposed which extend two alternative approaches to refutation