Estimation Technique: Wideband Delphi

Software effort and size estimation is the most critical part of the software development activities — at least for me. This is one of the biggest factor that will determine the success or failure of your project. A “real” successful project will mean project delivery on schedule, product is of just enough quality, and customer satisfaction. And we all know that a miscalculated effort required, weather a lack or an abundance, would mean less customer satisfaction, not finishing the project on schedule, and the quality of the product might be compromised.

I like involving my development team in estimation sessions. This gives them a sense of ownership — that we, the team, decided on how long and how much effort the project will need and that nobody is to be blamed if the estimates are very far from the actual effort.

One of my favorite estimation technique that involves “experts” or the developers in my case is the Wideband Delphi estimation technique. The idea of this technique is actually very simple: Gather a group of experts (of different expertise required for your project), give them an overview and a list of components of the project, and let them give an estimate independently. Then later on you can discuss with the team, review the estimates, determine the components where a majority does not have similar estimates, and come up with a consensus. Easy right?

The drawback of this technique is that it does not rely on historical data but instead relies on the intuition and insight of the estimators. You should be careful in picking the estimators in this kind of technique. Make sure that your estimators has enough experience on the field of expertise that your project will require to produce reliable estimates.