Managed operations / planning tool
Model the admin workload before agreeing a retainer.
A user count alone does not predict your monthly support need. Work through recurring tickets, people changes and governance, then decide what requires a named administrator and what stays with the business.
Build the real service scope from the workload
Keep a month of ticket categories and handling time, and distinguish routine access changes from specialist engineering. Customer authorisation time should not be counted as provider work. Review joiner/leaver steps against the organisation's retention and approvals policies before setting a monthly support commitment.
Administrator responsibility matrix · Service pricing framework