[mathattack]

There are two types of productivity:

1) Are you doing the right things?

2) Are you doing things right?

They can be imprecisely measured, but every metric has problems and can be gamed. Combining the measurements is extremely difficult.

Let's start with 1 - doing the right things. Someone who chooses to have their team work on 3 high value tasks, and stops their early on 6 low value tasks is by one definition more productive than someone who forces their team to do all 9 things. Or at the very least they are more effective. This is what Fowler is getting at.

On point 2... Let's assume that the appropriateness of what you are doing is immaterial. How fast are you doing it? This can be somewhat approximated. You can say "Speed versus function points" or "Speed versus budget" or "Speed versus other teams achieving the same output" and then bake in rework into the speed. All of these metrics are doable. Lines of code isn't a good base though.

The real question is, "What are you going to do with all of this productivity data?" If the answer is systemic improvement, you're on the right track. If you try to turn it into personal performance (or salary) then people wind up gaming the metrics.