I don’t know if this is appropriate for the question, but when I did metrics for our Service Desk, we tried to get an accurate count of First Call Resolution Rates. To do this, we used the Incident Categorization to filter out any Incident that the Service Desk would not normally be expected to answer.

Because our Service Desk was not allowed to work on Servers or Network Infrastructure, those categories were excluded. Although once a blue moon a Service Desk personnel could walk a user through a hardware issue, it was assumed that hardware issues had to be dispatched to a 2nd level for resolution, so those were excluded.

The point being is that we wanted to increase our First Call Resolution Rate for calls that could be reasonably resolved via a telephone support representative. Removing the “static” of Incidents that were beyond the scope of the Service Desk allowed us to better measure the improvements of the Service Desk.

If that is what you are trying to measure, then by all means, you should exclude hardware issues from your reporting.