يك نوع رابطه منطقي است كه نشان مي‌دهد، شروع كار فعاليت پس نياز به پايان كار فعاليت پيش‌نياز بستگي دارد. همچنین به تعاریف finish-to-start, start-to-finish, start-to-startو logical relationship. مراجعه نمایید

A logical relationship in which a successor activity cannot finish until a predecessor activity hasfinished. See also finish-to-start, start-to-finish, start-to-start, and logical relationship