According to Glen B. Alleman, cost, schedule, and technical outcomes are the three elements that compose all projects. They impact each other and react to those impacts dynamically in a triangle referred to as the “Three Body” problem. Alleman discusses in a blog post how to work around the problem to get the best out of our projects.
Simplifying the Equation
His post involves a lot of basic physics in order to help illustrate his point, but for your sake, let’s gloss over that. Alleman eventually gets to breaking down specifically the ways that cost, schedule, and technical performance affect each other:
- Cost is a function of schedule – Time is money in this case.
- Schedule is a function of cost – We can buy time, shorten schedule, but at what cost?
- Cost is a function of technical performance – Want to go fast? How much will that cost?
- Cost is a function of schedule – This is not a 1:1 exchange for the schedule question.
- Technical performance as a function of cost – What can we afford to do?
- Technical performance as a function of schedule – When can we have fast?
He says it is important to remember that none of these processes are fixed. They are all dictated by probabilities, and so it becomes your job to use the data available to you to make decisions based on the scenarios that provide the best chances of success. To hear this explanation in more elaborate depth, as well as accompanied by various visual aids, you can visit Alleman’s original blog post: http://herdingcats.typepad.com/my_weblog/2014/01/project-management-and-the-three-body-problem.html