What term refers to activities in a project that do not represent work and have a duration of zero?

The term that refers to activities in a project that do not represent actual work and have a duration of zero is a dummy activity. In project management, dummy activities are used in network diagrams, particularly in the context of the Critical Path Method (CPM) or Program Evaluation and Review Technique (PERT). They serve as placeholders to show dependencies between tasks without actually requiring resources or time to complete.

Dummy activities help to simplify the project network by illustrating the logical arrangement and relationships among different activities. For instance, if two tasks must occur in parallel, but one task must start before the other can finish, a dummy activity can be inserted to connect these tasks without indicating that any real work is being done.

While a milestone also signifies a significant event or achievement in a project timeline, it is often marked by the completion of one or more activities and can carry implications of real progress. Non-work activity and dummy task are not standard terms in project management terminology. Thus, the identification of dummy activity as the correct response reflects a clear understanding of its function and meaning in project planning and scheduling.