Interesting article on performance measurement and the restraints of metrical assessment. We need to be able to measure what we do for justification, to ourselves and our management teams, that what we're doing is working (or not). But we mustn't neglect emotional engagement and passion when doing so. Using numerical metrics is comforting, but using alone is blinkered. Combining with instinct and 'gut feel' helps us better judge performance.
When you try to manage by the numbers, be they test scores, sales activity, or productivity measures, you drive towards mediocrity. Quantitative (numerical) measurements alone will never make an organization great, because it is the qualitative (non numerical) elements of performance that achieve greatness.