Answer
DBA_HIST_SERVICE_STAT holds this kind of data, but it isn't granted to IFSAPP, IFSADMIN, or similar application-level accounts by default — it may be accessible under IFSSYS, and is definitely accessible to SYS. If you're on IFS Managed Cloud, you don't have direct access to query this yourself; raise a support case with IFS requesting the relevant capacity/utilization information (an AWR report, for example) instead. If you're self-hosting, whether you can query it yourself comes down to whether your team holds SYS or IFSSYS database credentials.