Of course, what this didn't capture was the qualitative detail of his work: identifying bugs, deleting, adding, fixing, abstracting, simplifying. No single number can capture that.
Indeed, the great W Edwards Deming warned -- but who takes notice? -- that taking any measure (simple or complex) and rewarding or punishing according to it is asking to be gamed. Doing so made #3 in his list of seven deadly diseases:
1. Lack of constancy of purposeThat said, it's not to say that metrics can't be useful as a source of insight. I wonder whether a simple multi-dimensional metric on lines-of-code could be helpful.
2. Emphasis on short-term profits
3. Evaluation by performance, merit rating, or annual review of performance
4. Mobility of management
5. Running a company on visible figures alone
6. Excessive medical costs
7. Excessive costs of warranty, fueled by lawyers who work for contingency fees
Suggestion:
1. Lines of own code addedI envisage that collecting this kind of data on a weekly basis (say) could show interesting patterns for individuals over time, and corroborate gut feelings about who is refactoring vs adding functionality vs breaking stuff etc.
2. Lines of own code deleted
3. Lines of others' code added
4. Lines of others' code deleted
5. Lines of code deleted by others
Another aspect to consider is the scope of these metrics. Does one measure individuals, pairs, or whole teams? If the metrics were implemented for the whole team as a means of self-assessment changes over time could be due to external factors (changes in the kind of functionality requested, crunch times, etc.) or internal factors (learning, change of personnel, change of practices, etc.).