Safety instrumented system (SIS)

A safety instrumented system (SIS) is composed of sensors, logic solvers, and final control elements. Its purpose is to take the process to a safe state when predetermined conditions are violated. The document also lists emergency shutdown system, safety shutdown system, and safety interlock system as other terms for this type of system.

Source checked2/2 values · 2026-10-25System

Specification

1 source

Kind	system
Origin	ANSI/ISA-84.00.01 via NIST SP 800-82r3

Study notes

Composed of sensors, logic solvers, and final control elements.
Purpose is to take the process to a safe state when predetermined conditions are violated.
Other terms commonly used include emergency shutdown system (ESS), safety shutdown system (SSD), and safety interlock system (SIS).

Safety

Safety function: takes the process to a safe state when predetermined conditions are violated.