The system of planning complex processes whose components take time and have to be carried out in a given sequence, by calculating the longest path of planned activities to the end of the project, and the earliest and latest that each activity can start and finish without making the project longer. A critical path is the sequence that has no spare time, or float, in any of the activities, so that a delay in any component along the path would result in the delay of the entire project; this determines the shortest time in which the project can be completed.