CS 3300 FALL 2015 Software Metrics

Some Quotes When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge us of a meagre and unsatisfactory kind: it may be the beginnings of knowlege but you have scarcely in your thoughts advanced to the stage of Science – Lord Kelvin You cannot control what you cannot measure – Tom Demarco

SWEBOK Metrics are under Engineering Management  Establish and maintain measurement commitment (ensure relevance to organization mission)  Plan the measurement process (select measures and collection techniques)  Perform the measurement process (actually do it)  Evaluate measurement (check validity, look for improvement) Says nothing about what we actually measure in a software project.

Goal – Question – Metric (GQM) Develop the goals for productivity and quality for the project. Develop a set of questions that will characterize the goal, preferably in a quantitative manner Develop a set of metrics, that if collected would answer the question.

Example Goal: Increase programmer productivity during each iteration. Question: What is our productivity now? How does this change with our new process? Metric: Direct vs. Indirect project time. Lines of Code committed per day.

In Class Example Goal: Reduce the number of defects during pre- release testing.