Why collect measurements?

Two main reasons to collect measurements:

1. To track your project. A basic task of any software project manager is to track the project progress. Examples are the defect rate, the size of finished functionality versus not finished. A very good technique which reads this measurement and displays it in a graphical format is the burn-up/burn-down charts which are heavily used in Agile development.
2. To improve the process of producing software. Very similar to six-sigma projects, CMMI level 4 and 5 have techniques which starts with an evidence of a mal-functioning process (most commonly supported by measurements).Then, it digs into the root causes, and suggests corrective actions. Finally, it designs measurements to quantify the impact of corrective actions, and start over again. This ‘Continuous Improvement’ cycle is one of the techniques used in any engineering discipline.

Measurements are an invaluable means for management, especially for software development, which is a deep intellectual engineering discipline. I may safely say that without measurements, you may not reach good management decisions what so ever. One of the sayings that is said again and again in Balanced Score-Cards environments is that “you cannot manage what you cannot measure, and you cannot measure what you cannot define”, is really true.