Using techniques for planning projects which have precisely defined start and end criteria, e.g. time or cost, etc., and in which the complexity of the interrelationship paths between the events and activities of the project makes control very difficult.
Such techniques are most useful where the problem is one of directing a large number of concurrent activities directed towards the same goal, and have little to offer where the constituent activities must of necessity take place consecutively. The techniques take into account the need for first placing in their logical order the activities of the project thus enforcing a discipline which automatically shows how each activity depends on or constrains the others. A system is thereby provided for monitoring the progress of the project, for forecasting the effects of snags (time-lags or time cost increments) on the project as a whole, and for deciding which activities should have priority for resources.
The basic steps are: (a) preparation of a network of arrows in between event nodes (circles representing a milestone or other important stage of an activity or an event) in which each arrow represents one activity or sub-activity in the project, and the positions of these arrows in the network represent the, logical, preferred, or in some cases circumstance-dictated order in which the activities must take place; (b) estimation of the duration and least cost of the activity represented by each arrow (and possibly also the cost of each activity); (c) analysis of the network to identify the activities which are critical in the sense that they govern the over-all least duration of the project; and (d) preparation of a schedule for all activities. All the foregoing procedures are algorithmically provided in network planning computer software packages.