Early information systems were mainly built around secondary, administrative processes of the value chain (e.g. accounting). But since the internet came into use, more and more primary processes have become accessible to automation: customer acquisition, ordering, billing and, in the case of intangible goods such as software, even delivery. Hence an increasing part of an enterprise has to be modeled and a substantial part thereof is implemented, usually in an object-oriented programming language like Java. To facilitate this complex task, the MEMO methodology (Multi-perspective Enterprise MOdeling) allows the description of the enterprise on three levels