وابستگي ميان دو فعاليت در پروژه، يا بين يك فعاليت و يك رخداد كليدي در پروژه است. همچنين به تعاریف  Precedence Relationship  ،  finish-to-finish (FF)، finish-to-start، (FS), start-to-finish,  و  start-to-start نيز مراجعه كنيد.

A dependency between two activities or between an activity and amilestone. See alsofinish-to-finish, finish-to-start, start-to-finish, and start-to-start