Numbers bring clarity. When you define the goal in anything but numbers, the goal quickly becomes subjective and fuzzy. (Subir Chowdhury)

When you want to improve something you have to know where you stand and where you want to go, or else it isn't going to happen. But when you define the goal in anything but numbers, the goal quickly becomes subjective and fuzzy.
Numbers bring clarity. (Subir Chowdhury, The power of six sigma, p31)