Today every company of any size needs more or less complex information systems in order to be able to manage all its daily activities and to develop strategies for the future. The centrality of information systems in companies has grown in recent decades in parallel with technological innovation: the same technology, in fact, has "climbed" the different levels of the Robert Anthony’s pyramid. The aim of this thesis is to analyze how it is possible to integrate a legacy information system that has undergone multiple stratifications and customizations over the years with a service-oriented architecture that is compatible with all features characterizing the most recent information systems.