User modeling facilitates use of a UML user model to define roles, goals, and tasks inside an organization, and defines how the roles, goals, and tasks relate to business entities within the organization. This information can be used to generate a user interface (UI) that facilitates management of the defined business entities within the organization. Each task defined inside the model, which may be represented as a stereotyped class in the UML class diagram, has a number of explicit steps associated with the task. These steps are outlined in UML activity diagrams and defined in a task interaction pattern. A modular approach to constructing UML activity diagram using the task interacting pattern to reduce the size of the model permits greater flexibility in generating the UI.