"The party (individual, project, or organization) responsible for accepting the product or for authorizing payment. The customer is external to the project (except possibly when integrated teams are used, as in IPPD), but not necessarily external to the organization. The customer may be a higher level project. Customers are a subset of stakeholders. (See also "stakeholder.")
In most cases where this term is used, the preceding definition is intended; however, in some contexts, the term "customer" is intended to include other relevant stakeholders. (See also "customer requirement.")"