Process-systems operators today face increasing demands for lower costs and higher safety standards in an increasingly regulated environment. In addition, companies desire to provide a working environment that is as safe as possible. As a result, plant owners strive to improve operation and safety of their assets, and extend the lifecycle to maintain profitability.

Safety instrumented systems (SIS) are an important part of this process and fire and gas protection systems form an integral part of risk management. This paper provides operators and designers of process plants an overview of the current approaches to risk reduction and the methodology required to comply with new standards for instrumented systems such as IEC 61508 (functional safety of electrical / electronic / programmable electronic safety-related systems).