Critical path method

The critical path method, often abbreviated CPM and also called critical path analysis, is an algorithm for scheduling a set of project activities. It identifies the longest stretch of dependent activities and measures the time needed to complete them from start to finish, and from the activity durations and dependencies it works out the earliest and latest times each activity can start and finish. It was developed in the late 1950s by Morgan R. Walker of DuPont and James E. Kelley Jr. of Remington Rand, at about the same time as the PERT technique with which it is commonly used. Any project with interdependent activities can use it, including construction, aerospace, software development and plant maintenance, and it was first applied in 1966 to the construction of the former World Trade Center towers in New York City.