A sequence of steps, tasks, or activities that converts inputs to outputs. A work process adds value to the inputs by changing them or using them to produce something new. Some processes may be contained wholly within a department or function (that is, accounting, marketing). However, the critical areas of work performed by an organization usually involve processes that cross functional or departmental boundaries. These are cross-functional processes. Processes are composed of sub processes that in turn consist of a group of related activities (e.g. order entry). Activities consist of groups of related tasks (e.g. writing an order). Tasks are elementary actions of work (e.g. time stamping an invoice).