Web Performance Matters

My post on The Importance of Measurements highlighted Lord Kelvin's famous statement that "if you cannot measure, then your knowledge is meagre and unsatisfactory", and the modern saying that "you can't manage what you can't (or don't) measure." Both advance the notion that measurements are indispensable.

I also discussed the origin of the second saying, which is very widely quoted, but rarely attributed to anyone. People sometimes cite Peter Drucker or W. Edwards Deming, but it seems fairly certain that both of those attributions are mistaken. I had tried previously to track down the origin of this saying, without success -- see Deep Thoughts on Management.

But this time around, I made progress, reaching the tentative conclusion that the popular saying may be an adaptation of Tom DeMarco's words, "you can't control what you don't measure." Tom DeMarco began his 1982 book, Controlling Software Projects: Management, Measurement, and Estimates [Amazon], with these words.

So I thought I should publicly correct my previously expressed doubts about DeMarco's authorship. For more details about why I changed my mind, see my two updates near the end of that post .

I'd still like to know how and when DeMarco's version morphed into its present popular form, and ideally who was responsible for that evolution. That may be harder to track down, but if you're interested, there's a Performance Forum thread where you can contribute your thoughts about this subject.

A universal rule of management?

One important caveat: DeMarco was writing primarily about software engineering, yet his words have now been adapted and they are typically cited as a universal rule of management. Yet even software engineers question their applicability in their own field! This leads to some interesting debates. I'll have more to say about that in my next post in this series.

This post is the first in a new series on management wisdom.
Tags: management wisdom, performance, Tom DeMarco, Kelvin, Drucker, Deming, software engineering, measurement, management