The activity description for a particular schedule activity typically will consist of a brief phrase or label that is assigned to that schedule activity to assist in the differentiation of that particular schedule activity from all others. These activity descriptions are typically used in conjunction with an activity identifier to further assist in their differentiation. The activity description traditionally will be based in some sort of scope of work determination of the schedule activity. The activity description also should, when possible, be provided forth in a clear, concise, and easy to understand manner. Activity description can also consist of a specific statement or label specifying what must be done to achieve a desired result in completion of this schedule activity. Of potentially most importance, the activity description must easily identify any schedule activity to any recipient of the schedule, regardless of how knowledgeable of other aspects of the project that the recipient may or may not be.
This term is defined in the 3rd edition of the PMBOK but not in the 4th.