When we hear about a process, a technique, or a tool, ask in what unit of measure are you assessing the beneficial outcome of applying those?
This idea started with P. W. Bridgman's principle that the meaning of any concept is in its measurement or other test. This was put forth in the 1930's in which Bridgman made a famous, useful, and very operational statement, usually remembered as:
The scientific method is doing your damnedest, no holds barred. †
Developing software is not a scientific process, even though Computer Science is a discipline at the university level, where probability and statistics are taught, IEEE/ACM Computer Science Education Curricula
When we want to make choices about a future outcome, we can apply statistical thinking using the mathematics used in scientific discussions - cost, schedule, and performance (C,S,P which are random variables).
These decisions are based on the probabilistic and statistical behavior of the underlying processes that create the alternatives for our decisions. Should we spend $X on a system that will return $Y value? Since both X and Y are random variables - they are in the future - our decision making processes needs to estimate the behaviour of these random variables and determine the impact on our outcomes.
When we hear there are alternatives to making decisions about the future impacted by cost, schedule and technical performance without estimating the impact of that decision, we need to ask what are those alternatives, what are their units of measure, and when can we find them described?
For those interested in further reading on the topic of Decision Making in the Presence of Uncertainty
- "Decision Making in the Presence of Uncertainty," Milos Hauskrecht, University of Pittsburgh.
- Assumption Based Planning: A Tool for Reducing Avoidable Surprises, James A. Dewer, Cambridge University Press and RAND MR114.
- Making Hard Decisions: Introduction to Decision Analysis, Robert T. Clemen, Duxbury Press
- Forecasting Methods and Applications, Spyros Makridakis, Steven C. Wheelwright, and Rob J. Hyndman, John Wiley & Sons. Hyndman has many forecasting books at his OText site as well as many solutions to forecasting problems at his Home Page.
† Reflections of a Physicist, P. W. Bridgman, pp. 535. The passage reads, "The scientific method, as far as it is a method, is nothing more than doing one's damnedest with one's mind, no holds barred."