Framework for change notification and view synchronization in distributed model management systems

Large-scale model management systems are increasingly in demand to support groups of users in collaborative work environment. Users of such systems share common models but approach them with different views depending on individual needs and skills. Since models change along with the reality that is captured in them, so should their dependent models and views. This calls for a mechanism to manage and synchronize such changes in the models and views so that the integrity of the modelling environment can be maintained. In this paper we propose a framework for change notification and view synchronization in distributed model management systems that (1) manages the dependency relationships between the shared models and the dependent user views and (2) coordinates the changes by way of controlling and communicating the propagation activities. The framework identifies the change requirements based on the locus of changes in shared models and the effects of such changes in the dependents. It further defines change management constructs and processes to establish a view synchronization mechanism. In the framework, structured modeling was adopted for the representation of mathematical models, the generic model concept for constructing and dealing with mathematical models and the object-oriented database management system (ODBMS) to combine them in a single formalism. We present a prototype distributed model management system that has been developed to substantiate the efficacy of the proposed framework. The prototype was implemented on Windows NT using C++ and a commercial ODBMS called ObjectStore.