L-P Huberdeau's blog

Estimating the duration of a software project is a fairly simple task. It’s a common misconception that it requires many years of experience and only few actually succeed. Many projects fail because they are underestimated. The reason is not that the estimate was wrong, it’s that there were probably no estimation at all. Staring at the ceiling for a few minutes and writing down a number is not an estimate, it’s simply a guess. Some are quite talented at guessing, but it doesn’t make their final number more valuable.

What makes a good estimate? I would be quite nice if two different estimators could reach a similar value. Even better, it would be good if those estimators could defend their estimates months later. It has to be possible to track the source of the values produced. This is possible. Estimation has nothing to do with arcane magic, it’s simply about following a few steps and taking them seriously. There are two things you need to know about: how to count and know how good you are. The first step is learning how to count. How do you know how big what you have to develop is? Once you know how to count, it’s only about collecting data and you will find out how good you are. It doesn’t take that much data to obtain accurate results. A simple average based on your last project will give you a value that’s closer to reality than a guess.

Where does the misconception about estimation come from in the developer communities? There are dozens of books being written on the topic, quite a few of them being best-sellers. If they are best-sellers, why don’t you ever hear about a developer systematically making accurate estimates? It probably has something to do with most of the developers you hear about are blogging, work with bleeding edge technologies and never bothered reading a book unless it had Web 2.0 in the title. The software engineering knowledge about estimations come from military industry and gray-haired consultants. No need to say, it doesn’t really reach web development.

I have been experimenting with some of the techniques recently, applied to web applications. I have to admit the results were impressive. I didn’t need to spend tons of hours filling speadsheets or write a thousand page of documentation. In the next few weeks, I will discuss of certain aspects of my experimentation. Stay tuned.