The myth of PERT: all the decisions have been made

Mr. Holifield…. If we can find some way of doing the preliminary work and clarifying the type of project that you are going to want… in advance. I don’t know how this is going to be done… We have seen too many of these systems progress from a relatively small investment to being with and get along the path of $400 million or $500 million, and then we find out that we started on the wrong path.

 

Mr. Bell. Or it is going to cost twice as much as we thought it was.

 

Mr. Holifield. Yes.

 

Mr. Bell. Maybe if we had known in the first place it was going to cost twice as much, we wouldn’t have started.

 

Mr. Holifield. We are going to look at this PERT system very closely, because to me looking at it as a businessman, it seems that it is very sound in concept.

 

Mr. Bell. Yes. Several of us attended a presentation on that earlier this week. I think it is a method of achieving a very orderly consideration of the series of steps that are involved in accomplishing anything. There is no magic in it. It isn’t so much a decision-making process as a planning process. It schedules the stages of effort that are necessary and the particular points on which decisions are required.

That was David E. Bell (Director, Bureau of the Budget) conversing with Representative Holifield in 1962.

The conversation was on PERT, the forerunner of today’s Earned Value Management System.  Notice how Bell distinguished the decision-making process from the planning process. It was expected that all the decision-making was done up-front through a systems analysis, which formed the basis of contractor proposals. Once a proposal was selected, the PERT cost/schedule process was merely outlining all the steps implicit from the policies already made.

Of course, such detailed planning constrains actions and locks-in technical approaches. It assumes that the people on the ground do not need to contribute, they simply execute standing orders. The whole PERT/EVMS system precludes the idea of novelty, that we might actually learn new information in the execution of a development project.

And yet this is still the standard process of doing things in the 21st century, at least for the Department of Defense.

Source: “Systems Development and Management (Part 1).” Hearings before a Subcommittee of the Committee on Government operations House of Representatives Eighty-Seventh Congress, Second Session, June 21 August 15, 1962. U.S. Government Printing Office, Washington: 1962.