Application downtime is getting lesser and lesser with Cloud computing. Users are more demanding without the need of downtime. Thus, we need to move to the approach of hotfix and high availability environment.
Shift to Zero Downtime
The design of zero downtime will require a digital transformation approach to your entire architecture. Another consideration is utilisation of the Cloud platform for different high availability approach. As this approach will incur additional cost like licences, you may want to evaluate a switch to pay as your use model instead of fixed licensing.
Development with No Downtime
Another key change is your development approach. This must be changed to reflect deployment with no downtime. Instead, hotfix and patches must be applied seamlessly without any downtime or impact to user operations. Therefore, your development will need Agile and DevOps to enable this approach.
If you have intention to move to a services with no downtime, it is time to reform your architecture and development approach. This involves utilisation of Cloud platform and Agile development to achieve this vision.
Danny Kwok 