From “How Will You Measure Your Life?” by Clayton M. Christensen, James Allworth, and Karen Dillon
Let me explain in management terms: police chiefs need to look at the numbers of each type of crime, over time, to know whether their strategy is working. The manager of a business cannot see the complete health of the company by looking at specific orders from specific customers; he or she needs to have things aggregated… In short, we need to aggregate to help us see the big picture. This is far from an accurate way to measure things, but this is the best that we can do.