We schedule a point release every quarter, with a major release once a year. A breakdown of releases for example can be found in our T-Plan Robot Enterprise Versions document.
We also have an OTA (over the air) update mechanism, where customers can get automatic upgrades & updates to bug fixes etc. When bugs are reported we are not beaten by anyone in our speed to get these turned around. Where applicable these fixes can be released as a ‘point.point’ release; to a specific customer, or the customer base as a whole.