Plant supply redundancy, electrical reliability What equipment needs to be redundant and when to stop?

This paper is written to help users to make the right decisions about what devices in a plant supply need to be duplicated and how to decide when it is no longer appropriate. In the first part of this paper the mathematic theory behind the mechanism of failure is explained. This is followed by a chapter that explains the different strategies that can be followed to cope with failures. Redundancy as one of these strategies and will be explained in more detail in a separate chapter. The second part of the paper explains how these strategies are implemented in practice looking more closely at power supply. The paper finishes with rules of thumb for configuring a power supply.