Pert, Cpm, and Agile Project
PERT, CPM, and Agile Project Management.
Robert C. Martin 5 October 2003 Some time in the late 60's my father brought home a book that he thought I'd be interested in. The title was Introduction to Operations Research by Frederick S. Hillier and Gerald J. Lieberman, Holden-Day, 1967. I was probably 15 or 16 years old. The book languished on my shelves for perhaps ten years. Then, as a young software professional, I pulled the book down and ,thumbing through its pages, I noticed a chapter on PERT. I had heard of PERT as a method of project management, so I started to read and learn. Since those days in the early 80's I have seen dozens of examples of PERT charts, and tools for drawing PERT charts. They always make me cringe. Invariably these charts a tools missed the nd fundamental principle of PERT that made it such a successful technique: the management of probabilities. PERT (Program Evaluation and Review Technique) was developed in 1958 to help measure and control the progress of the Polaris Fleet Ballistic Missile program. The technique earned considerable respect for assisting in the management of thousands of different contractors and agencies, and is credited with helping to advance the completion date of the program by two years.
PERT: an overview.
PERT is a technique for estimating and planning a large project. One of its most powerful concepts is that project management is the management of probabilities. PERT makes use of simple statistical mathematics in order to come up with a probability distribution for the completion dates of the project milestones. For example, in PERT tasks are estimated with three numbers: The best case, the nominal case, and the worst case. These three estimates are combined into an expected duration, and a standard deviation. Thus the duration of each task is presumed to be a random variable with a known distribution. The math is very simple. Consider a task whose best/nominal/worst estimate is 3/5/9. The expected
Robert C. Martin 5 October 2003 Some time in the late 60's my father brought home a book that he thought I'd be interested in. The title was Introduction to Operations Research by Frederick S. Hillier and Gerald J. Lieberman, Holden-Day, 1967. I was probably 15 or 16 years old. The book languished on my shelves for perhaps ten years. Then, as a young software professional, I pulled the book down and ,thumbing through its pages, I noticed a chapter on PERT. I had heard of PERT as a method of project management, so I started to read and learn. Since those days in the early 80's I have seen dozens of examples of PERT charts, and tools for drawing PERT charts. They always make me cringe. Invariably these charts a tools missed the nd fundamental principle of PERT that made it such a successful technique: the management of probabilities. PERT (Program Evaluation and Review Technique) was developed in 1958 to help measure and control the progress of the Polaris Fleet Ballistic Missile program. The technique earned considerable respect for assisting in the management of thousands of different contractors and agencies, and is credited with helping to advance the completion date of the program by two years.
PERT: an overview.
PERT is a technique for estimating and planning a large project. One of its most powerful concepts is that project management is the management of probabilities. PERT makes use of simple statistical mathematics in order to come up with a probability distribution for the completion dates of the project milestones. For example, in PERT tasks are estimated with three numbers: The best case, the nominal case, and the worst case. These three estimates are combined into an expected duration, and a standard deviation. Thus the duration of each task is presumed to be a random variable with a known distribution. The math is very simple. Consider a task whose best/nominal/worst estimate is 3/5/9. The expected