JTB FlexReport Detailed Reports now has three reports that can help you determine if the denials are unacceptable so you need to purchase more licenses or restrict usage of licenses for certain users or reserve licenses for some.
Some companies has a license policy that denials should never happen while others can accept it to a certain degree.
The following report shows when a user/host was denied the first and last time as well as if a license eventually was checked out soon after the last denial, and finally how many denials there was during this period.
Here is a report that shows the denials on a monthly basis.
JTB FlexReport also supports distributed license servers so denials that happens on one server where the request fall over to another server that eventually gives a license to the user will not be counted as a denial. Settings for creation of distributed license server groups can be done in JTB FlexReport Config.
If you want to try JTB FlexReport a free trial is available upon request with full support without any cost during the trial period so you can make sure it works as expected.
See also FLEXnet denial reports with JTB FlexReport that describes how to grant access to the log files from the service.