Work performed by people, The rolling stock ca..., technologies, or The physical plant, .... Activities are usually described by the action-verb-adjective-noun grammar convention. Activities may occur in a linked sequence and activity-to-activity assignments may exist. (1) In activity-based The branch of accoun..., a task or activity, performed by or at a resource, required in producing the organization’s output of A merchandise or mat... and services. A resource may be a person, machine, or facility. Activities are grouped into pools by type of activity and allocated to products. (2) In project management, an element of work on a project. It usually has an anticipated duration, anticipated cost, and expected resource requirements. Sometimes major activity is used for larger bodies of work.