A dummy activity in project management is an artificially introduced activity that is used to maintain logical relationships between other activities. It is represented by a dotted line in project network diagrams, such as the arrow diagramming method (ADM) or the precedence diagramming method (PDM). A dummy activity does not consume any time or resources and is solely used for establishing dependencies and sequencing of other activities in the project.
The independent float, also known as free float, affects only the particular activity involved.
The definition of free float for any activity is the difference between its earliest finish time and earliest start time for its successor activity.
