[citation needed] The A Guide to the Project Management Body of Knowledge (PMBOK Guide) does not define the term dependency, but refers for this term to a logical relationship, which in turn is defined as dependency between two activities, or between an activity and a milestone.
Sometimes it is necessarily to overlap activities; an option may be selected to use start-to-start (SS), finish-to-finish (FF) or start-to-finish (SF) relationships....Whenever possible, the FS logical relationship should be used.
The critical chain method necessitates taking into account resource constraint-derived dependencies as well.
In accordance to PMBOK a lead is "the amount of time whereby a successor activity can be advanced with respect to a predecessor activity For example, on a project to construct a new office building, the landscaping could be scheduled to start prior to the scheduled punch list completion.
[5] Real life examples, which are simulated by Maximal-Type Relation: Maximal-type relationships are rarely implemented in the project management software, most probably because with this feature it is too easy to create contradictory dependencies.