Why did Diocletian increase the number of Roman mints?

Diocletian increased the number of Roman mints from 8 to 15 as part of a broader program of monetary reform intended to stabilize the empire's finances and stave off economic crises.1

This decentralization of minting was implemented alongside the restoration of sound gold and silver coinage of a fixed design, the creation of a new bronze coin, and the circulation of small coins to facilitate daily financial exchanges. These efforts were designed to address the legacy of an unstable financial situation and support the emperor's extensive domestic reforms, which included increased military spending and administrative restructuring.1