In project management, a critical path is the sequence of project network terminal elements with the longest overall duration, determining the shortest time to complete the project. Project Management is the discipline of defining and achieving targets while optimizing the use of resources (time, money, people, materials, energy, space, etc) over the course of a project (a set of activities of finite duration). ... A project network is a graph (flow chart) depicting the sequence in which a projects terminal elements are to be completed by showing terminal elements and their dependencies. ... In project management, a terminal element is the lowest element (activity or deliverable) in a work breakdown structure(WCS); it is not further subdivided. ... Duration of a projects terminal element is the number of calendar periods it takes from the time the execution of element starts to the moment it is completed. ...

The duration of the critical path determines the duration of the entire project. Any delay of a terminal element on the critical path directly impacts the planned project completion date (i.e. there is no float on the critical path). Float in project management is the amount of time that a terminal element in a project network can be delayed by, without causing a delay to: subsequent terminal elements (free float) project completion date (total float). ...

A project can have several, parallel critical paths. An additional parallel path through the network with the total durations just shorter than the critical path is called a sub-critical path.

Originally, the critical path method considered only logical dependencies among terminal elements. A related concept is the critical chain, which adds resource dependencies. In a project network, a dependency is a link amongst a projects terminal elements. ... In project management, the critical chain is the sequence of both precedence- and resource-dependent terminal elements that prevents a project from being completed in a shorter time, given finite resources. ...

The critical path method (CPM) was invented by the DuPont corporation during the 1950's. The DuPont Corporation was the Prime Contractor for the Hanford Engineering Works, a part of the Manhattan Project during World War II that was located at Hanford, Washington. ...

See also

• List of project management topics
• PERT
• Project
• Project management
• Project planning
• Work breakdown structure