Outsourcing is a service defined as the result of an integration of a set of basic services, aiming at entrusting to an IT service provider all or part of the information system (IS) of a customer, within the framework of a multi-year contract, on a fixed basis, with a level of service and a defined duration. In other words, it is the outsourcing of all or part of the management and operation of the IS to a third-party IT service provider. This service is provided on a long-term basis and not on a one-off basis.