Every issue that comes back as a second or third contact costs you again. This shows what those repeats cost a year, how much of that is realistically within your control, and how much could turn into cash. It also tells you plainly when a project to raise FCR (first contact resolution) would not pay back.
Once the diagnostic is complete you will see the burden, how much of it is controllable, how much converts to cash, and whether the project pays back.