Networks diagrams are, in effect, method statements in pictorial form. They represent the way that activities will be performed in order to achieve the objectives. These techniques were first used in the 1950’s and variants were simultaneously developed on both sides of the Atlantic.
There are two main formats for preparing a network diagram: activity-on-node (the most common form of which is precedence diagram and activity-on-arrow. Both formats achieve the same result but since 1985 precedence has become by far the more widely used, mainly due to the widespread use of scheduling software.
Network analysis is the collective term for the different ways in which a network diagram may be analysed, including for example, critical path analysis, resource limited scheduling, Program Evaluation and Review Technique (PERT), Monte Carlo analysis and critical chain.