Use of an outside business services vendor (and its supervised personnel), either on the customer’s premises or off-site at the vendor’s location, to perform a function or run a department that was previously staffed and supervised by the customer directly. (Sometimes, but not necessarily, limited to situations where some or all of the customer’s previous staff performing that function are hired by the outsourcing vendor.) In Europe, certain legal obligations are placed on the outsourcing company. For example, in the United Kingdom, a formal Transfer of Undertakings Procedure (TUPE) applies to outsourced functions whereby the contracts of employment of all staff within the affected area are automatically transferred to the new employer, which then takes over all rights and obligations arising from those contracts of employment, except criminal liabilities and pension obligations.
Source: Staffing Industry Analysts