Gestion de l'évolution dans les bases de connaissances : une approche par les règles. (Evolution management in knowledge bases : an approach using rules)

The work presented in this thesis concerns schema and object evolution in knowledge based systems. It is realized in the framework of the knowledge representation system Shood. We try to solve extensibility and reuse problems for evolution mechanisms. We propose an evolution system which allows the definition and the management of the dynamics. This management is realized by a set of mechanisms, such as instance classification, active rules, and a set of modification operations called the evolution support. We propose also a mechanism based on evolution rules and strategies to allow the declarative expression of constraints for structures and data evolution. The designer can define strategies to organize these constraints. According to his needs, he can define multiple strategies, but only one will be active at a given moment. The mechanism implementing evolution rules and strategies is developped mainly by mapping between an evolution rule and several active rules, and between a strategy and a rule base.