Outsourcing describes the medium to long-term outsourcing of inhouse tasks and resources to a legally distinct service provider. “Make-or-Buy” gives an answer to whether an in-house production or an external procurement should be preferred. There are two types of outsourcing – “total outsourcing” (all tasks are completely outsourced to one provider) and “selective outsourcing” (the tasks are outsourced to several providers). In most cases of selective outsourcing, the “Best-of-Breed”-approach is used as a basis.