That's a good question: Why are departments not tracking that information? For example, the progress they are making towards digitizing the client or citizen services and the potential savings that are derived from this increased digitization is, in my opinion, a missed opportunity to track what is potentially a good story when the government is digitizing services from end to end, because it can lead to substantial savings.
For example, processing a tax return or an application electronically costs significantly less than processing it manually, whatever the system is or the process is. Doing that end to end electronically costs significantly less than doing it in person or through call centres. The government doesn't seem to be tracking these savings, or certainly not to a significant extent.