I would start with the XLIST option on the
QUTL utility menu, which lists all of the individual xlocks. Hopefully that will product an AHA! moment where you suddenly recognize where all the xlocks are coming from. For example, it could be one rogue program, job, or user that is responsible for most of the usage. Or, as Frank suggests, it might just that there has been a steady increase in the number of files opened. (Of course XLOCK does not explicitly identify the resources being locked, but it is common to use the first value for the file channel and the second for the record number.)
It may just be that you need to increase the
QUEUE statement value in the MIAME.INI to account for a steady upward creep in usage.