A system is described for controlling access to resources using an object model. Users can specify use cases for accessing resources. The user may be granted access if the user satisfies qualifications required for accessing the resource, selected a use case permissible for accessing the resource, and satisfies qualifications required for the use case. Use cases, qualifications, resources, and/or links between them can be implemented using an object model. The system can be used in addition to authentication and authorization.