Often, organizations externalize work activities and use employment intermediaries (consulting firms, temporary help agencies, contract companies (Nesheim, Olsen, & Kalleberg 2007). At a functional level, firms tend to externalize business as well so that boundaries of firms are extended. Historically production function, catering, cleaning, security, IT functions have been outsourced for several years. HR outsourcing is far more recent. Several elements will be discussed: HR outsourcing definition, typology, process management, and research perspectives on performance.