Machine Operating Speed, Fault Security and Fault Tolerance for Performability Analysis in Industrial Automation

This paper focuses on FPGA-based controllers in the context of industrial automation. For high reliability applications, fault tolerance is often used. Fault security is another important aspect in these applications. Furthermore, machines are often operated at a lower-than-nominal speed. A Performability model is developed which simultaneously incorporates the effects of fault tolerance, fault security and different machine speeds on machine behavior. Another contribution of this paper is the derivation of an expression to obtain the average yearly cost of downtime as a function of the level of fault security of the design.