Project management was not used as an isolated concept
before the Sputnik crisis of the Cold War. After this crisis, the United States Department of Defense needed to speed up the military project process and new
tools (models) for achieving this goal were invented. In 1958 they invented the Program Evaluation and Review Technique or PERT, as part of the Polaris missile submarine program. At the same time, the DuPont corporation invented a similar model called CPM, critical path method. PERT was later extended with a work breakdown structure or WBS. The process flow and structure of the military undertakings quickly spread into many private enterprises.
There are a number of guiding techniques that have
been developed over the years that can be used to formally specify exactly how the project will be managed. These include
the Project Management Body of Knowledge (PMBOK), and such ideas as the Personal Software Process (PSP), and the Team Software Process (TSP) and PRINCE2. These techniques attempt to standardize the practices
of the development team making them easier to predict and manage as well as track.
Critical chain is the latest extension to the traditional critical path method.
In critical studies of project management, it has been
noted that several of these fundamentally PERT-based models are not well suited for the multi-project company environment
of today. Most of them are aimed at very large-scale, one-time, non-routine projects, and nowadays all kinds of management
are expressed in terms of projects. Using complex models for "projects" (or rather "tasks") spanning a few weeks has been
proven to cause unnecessary costs and low maneuverability in several cases. Instead project management experts try to identify
different "lightweight" models, such as, for example Extreme Programming for software development and Scrum techniques. The generalization of extreme programming
to other kinds of projects is extreme project management, which may be used in combination with the process modeling
and management principles of human interaction management.