A method for modeling an enterprise application to be performed over multiple tiers in a distributed computer system. The method includes generating a model, such as a sequence diagram, of the enterprise application showing the tiers with standard responsibilities assigned to a client tier, a Web tier, a business logic tier, and an enterprise information system tier. The standard functions are assigned by identifying protocol services and mapping these to the tiers. Business functions for the application are identified with use cases. The basic business services are then mapped to the enterprise application model. This model is then further modified, such as by subdividing the tiers into subtiers, and mapping the detailed business services to the appropriate tiers. The method continues with identifying of architectural goals or capabilities and modifying of the enterprise application model to map or implement the architectural services associated with each goal to the tiers.