Enterprise Resource Planning (ERP) Systems, that have been implemented these last years, constitute major advantages for the enterprises that know how to take advantage of them. Conceived at the beginning to improve and automate operational processes, the systems have now big ambitions: supplying information for activities drive, make simulations and support in decision making. ERP provide an integrated core for the enterprise by offering a standardized information system. One ERP include a large range of tasks, from production and financial systems to human resources. ERP is a collection of software programs that include all the tasks of an enterprise, no matter how varied are those.