For a variety of reasons, it is often the case that only a subset of the schedule activities is analyzed. Sometimes a specific operation is under scrutiny, other times a specific subcontractor’s tasks are examined, or a fragnet of a specific collection of activities is analyzed. Additionally, schedules with several thousand activities, or even several tens of thousands of activities are becoming increasingly common. Such jumbo or mega schedules are inherently difficult, if not impossible, to analyze at a meaningful level of detail without breaking them down first.
Analyzing a subset layer of activities introduces a new set of assumptions and challenges. To name only a couple of such assumptions and consequent challenges, the dates of the first activities of the various subset paths are assumed to be accurate and fixed. Exclusion of activities which are not a part of the subset but are in the middle of a path may cause an artificial path discontinuity.
The concept of Edge Activities is to introduce a necessary companion subset of activities that are connected as predecessors, successors, or both to one or more of the primary selected subset of activities being examined. An Edge Activity, as such, is defined as an activity which is not part of, but is directly connected to one or more of, the activities in the selected subset.