|What:||Defining and using a coherent set of project measures.|
|When:||Project planning and execution.|
|Results:||Encouragement of desired behaviors, objective baselines for measuring progress and performance, and timely triggers for action.|
Before deciding what to measure on projects, define the behaviors you seek. Measurement affects behavior, so clearly define desired results and use them to guide selection of metrics.
There are three types of metrics: predictive, diagnostic, and retrospective. Useful systems of metrics will generally include a good balance of measurement types.