When seeking PLC controller failure rate estimates, knowing what the rate is is not as important as knowing the cause of the failure. Looking at MTBF (failure rate) stats are essential, but you should be using the data as a means to solving the bigger problem. The Business Industrial Network (BIN) says questions you should ask include: what parts and how many should you stock, ways to improve equipment reliability, is a PLC controller the best option?, etc. In this article, BIN lists four factors that increase failure rates and five module types that should be considered independently.
