The purpose of EAI (Enterprise Application Integration) is the interoperability and organization of the flow of information between heterogeneous applications, i.e. ensure communcation between the different applications making up the information system of the company, even those of clients, partners, or suppliers.
An EAI project therefore involves, in the first place, implementing an architecture under which the different applications communicate with each other. This therefore involves the development of connectors (middleware) which make it possible to interface applications by using different communication protocoles (generally proprietary).
However, the EAI projet goes beyond interoperability between the applications: it makes it possible to define a workflow between the applications and therefore represents an alternative to ERP with a more modular approach.
Nonethless, EAI still has the limits related with the rigidity of the legacy, since it is necessary to modify the middleware in the case of significant changes of the applications. Web services