An ontology-driven information system includes a plurality of models, each of which expresses an aspect of a business domain using concepts and relationships between concepts. An ontology, which is in communication with each of the plurality of models, provides uniform definitions for the concepts and relationships between concepts used in the plurality of models. A method for executing an interaction flow model includes receiving an event and categorizing the received event. Once the event is categorized, a situation that matches the categorized received event is identified. One or more tasks are then executed for the situation. The execution of the one or more tasks can include either an interpretation of a model or the execution of a method of an object. The information system also includes a user and application interface and a reasoning engine that is in communication with the user and application interface. A knowledge manager is in communication with the user and application interface and is interfaced with the reasoning engine. A distributed information service also is in communication with the reasoning engine, the knowledge manager, and the user and application interface.