Activity is the lowest planning unity and belongs to the work packages of the lowest level. It contains the information about work that is necessary for the achievement of the individual works.
Several work packages are also combined to one activity e.g. accompanying activity. It is described as a work step in the project management. Besides an activity includes the results of the analysis of the project environment, the existing working tools, the description of the objects and the project plan. It is the statement of the date activities that should be implemented to produce the different events of the project. To define an activity the work packages are subdivided into individual activities, which are applicable for the control, scheduling, implementation and monitoring of a project.
The definition of an activity is made by the agreement of the work scope, responsibility and duration. The activities are represented in the tabular list. They are given the specific characteristics or the work description for the further planning processes. The change requests can be proceed by the definition, but they are assigned to the change management.