Safety Instrumented Systems (SIS)

Duration: 5 days

Course Aim

This course will explain the essential requirements of the IEC 61511 standard for all stages of the safety project, from hazard and risk assessment studies to hardware and software engineering and the maintenance and proof testing regimes. We will also go over methods for avoiding spurious trips. You will learn about the meaning and implications of Safety Integrity Levels (SILs), how SIL targets are determined, the role of alarms in safety-critical applications, and the critical features of safety-certified PLCs.

Other topics covered include calculating failure probabilities for single and redundant Safety Instrumented Systems (SIS) designs, selecting instruments and controllers suitable for safety systems, managing the application software project for your safety system, and optimizing proof testing intervals.

Course Objective

At the end of the course, the trainee will be able to:

  • Describe the IEC 61511 safety life-cycle and be able to explain the primary inputs, procedures
    and outputs needed for project success.
  • Understand the fundamentals of management planning, practical responsibility assignment, and the procedures needed for projects involving functional safety.
  • Describe tolerable risk targets to the ALARP principle of risk reduction, including how the Safety Integrity Level (SIL) can be determined.
  • Understand the fundamentals of probability and explain how this applies to equipment failure and SIL verification.
  • Understand the fundamentals of functional safety standard IEC 61508 and SIL-capable hardware and software options.
  • Explain the main elements of a typical SIS, including fault-tolerant architectures of safety instrumented functions (SIF).
  • Summarise the need and principles of regular inspection and proof testing of SIF and SIS.


Course Content

  • Design considerations
  • Protection layers
  • Safety integrity levels
  • SIS evaluation
  • Hardware
  • Permissive and interlocks
  • ESD & PSD alarm systems Redundancy
  • Testing, resetting and bypassing Functional Testing
  • Managing the SIS
  • Control & safety systems integration

Who Should Attend?

This is essential training for anyone involved in designing, modifying, operating, and maintaining a significant hazard facility or other process plants who would like to improve their process safety knowledge.