High demands are often placed on SCADA and MES systems regarding availability, functionality, and uptime (ideally 24/7/365). Since every device has some kind of a lifespan and a failure rate, it is necessary to take care of these factors. Using redundancy is a way to increase overall system availability even when one or more components fail.
This is a companion discussion topic for the original entry at https://d2000.ipesoft.com/blog/do-you-need-to-use-redundant-systems-its-important-part-of-d2000/