Nowadays, if we want to obtain a sound and correct final software product it is very important to be able to properly join modern OO programming environments, which are built for the new Internet architectures, with the OO methodologies produced over the last few years in order to deal properly with the Conceptual Modeling process. Our contribution to this objective is the OO-Method [Pas96] proposal. OOMethod is an OO Methodology that allows analysts to introduce the relevant system information by means of a set of graphical models to obtain the conceptual model through a requirement collection phase, so that an OO formal specification in OASIS [Pas95] can be generated at any given moment. This formal specification acts as a high-level system repository. Furthermore, a Java software prototype, which is functionally equivalent to the OASIS specification, is also generated in an automated way. This is achieved by defining an execution model that gives the pattern to obtain a concrete im...