PERT/CPM: The lost science of project management?
When you think about it, Planning, Scheduling and Control lie at the heart of what’s expected of a project manager and could be considered the base skills everyone in the profession is suppose to have. CPM (Critical Path Method) and PERT (Program Evaluation Review Technique) are considered the “science” that drives the ability to plan, schedule and control a project.
With the advent of modern project scheduling tools such as Microsoft Project, not many people in the profession are knowledgeable in these techniques and that’s too bad as understanding it will make you better understand the process and method of how a software tool like MS Project works. And even if you shun traditional project management techniques in favor of simpler scheduling techniques like the resurgence of Kanban in Agile software development, it won’t hurt at all to have this base knowledge.
And speaking of Kanban, which has its roots in the Toyota Production System in the 70’s created by Taiichi Ohno, PERT/CPM has its roots from the 1950’s industrial and military initiatives. As the Intervention site states:
CPM/PERT or Network Analysis as the technique is sometimes called, developed along two parallel streams, one industrial and the other military.
CPM was the discovery of M.R.Walker of E.I.Du Pont de Nemours & Co. and J.E.Kelly of Remington Rand, circa 1957. The computation was designed for the UNIVAC-I computer. The first test was made in 1958, when CPM was applied to the construction of a new chemical plant. In March 1959, the method was applied to a maintenance shut-down at the Du Pont works in Louisville, Kentucky. Unproductive time was reduced from 125 to 93 hours.
PERT was devised in 1958 for the POLARIS missile program by the Program Evaluation Branch of the Special Projects office of the U.S.Navy, helped by the Lockheed Missile Systems division and the Consultant firm of Booz-Allen & Hamilton. The calculations were so arranged so that they could be carried out on the IBM Naval Ordinance Research Computer (NORC) at Dahlgren, Virginia.
Since I teach project management at several universities and also teach a MS Project class for PMI-LA, I felt it was imperative of me to learn about this technique more and a book I found in my research titled Project Management With Cpm, Pert and Precedence Diagramming first published in the 70’s is still relevant and for those who want to dive deep into this topic should borrow it from the library (might be hard to find) or buy it used on Amazon (see link below).
But for those impatient or want an overview first, here’s a great tutorial that’s about 30 minutes long and is one of the best online tutorials I found: