The precedence diagram method is an approach to project planning and scheduling that relies on a visual representation of activities and their relationships. This method can be used to create a clear, logical schedule that will flow appropriately to keep tasks on deadline. Some planners manually create a precedence diagram, while others may use software with this capability. Project planning software can have additional features, like tie-ins with forms and other materials to make the document interactive for the benefit of users.
One element in the precedence diagram method is the creation of nodes, representing activities. Each node is a box, with a notation about the kind of activity it represents. The nodes can be linked by arrows to illustrate their relationships. Some are isolated, and can be done at any time, without dependence on other activities as part of the project. These can be less important for planning, as they do not hinge upon or have the potential to hold up other events.
Other nodes can be performed at the same time and make multitasking available. These nodes provide a high degree of flexibility for schedule planning. Nodes with a high priority are those which require the completion of other tasks, or which need to be finished to allow other tasks to proceed. For example, a home needs a foundation before other construction activities can start. In the precedence diagram method, the foundation would take priority in the scheduling for the site.
It may be necessary to move nodes around to better illustrate and encapsulate their relationships to each other. Software can be useful for this, as it makes it easy to move components of the planning as necessary. Working on a whiteboard or other easily configurable surface while drafting a plan with the precedence diagram method can be advised, as drawing, redrawing, erasing, and moving nodes can be time consuming and irritating.
At the finish, a designer using the precedence diagram method should have a clear representation of what needs to happen to complete a project, and when it needs to happen. This information can help with the development of a schedule, as well as a project timeline to provide information about when clients can expect completion. The method permits companies to start organizing in advance to prepare for critical events, like stages of a project that could potentially hold up the whole project; thus, for example, a construction company can order supplies ahead of time to avoid a situation where workers stand around with nothing to do because a critical component is missing.