Start with responsibility
A response target means little if nobody knows which devices, applications and suppliers sit inside the contract. List them and name the owner for each dependency.
Make support easy to use
Set one request channel, support hours and a clear path for urgent incidents. Staff should know where to go without asking a manager first.
Review what keeps returning
A monthly report should show repeated faults, important changes and the work that deserves a decision. A list of closed tickets is not enough.