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The Safety Lifecycle

  • Published on Jan 30, 2025
  • 1 minute(s) read
  • Denis Tkalec
  • Tomislav Renic
  • Iva Vukovic

Diagram Description automatically generatedThe Safety Lifecycle (in IMS SIS).

The Safety Lifecycle, a cyclic process where all hazards are identified and analyzed, can be outlined in a few steps:

  • Determining the Hazard Scenario and Consequence (via a HAZOP study).
  • In case of a high Consequence, initiate a LOPA study.
  • During the LOPA, based on the Initiating Event frequencies, and Barrier PFDs, calculate the Overall RRF and Overall SIL level for the Consequence.
  • Evaluate the Overall SIL to assess the adequacy of the existing Barriers against the Hazard Scenario.
  • If the Overall SIL for the Consequence is not acceptable, start a SIF Analysis and determine the SIF’s minimum required RRF, i.e., its Target PFD, that achieves an acceptable Overall SIL level.
  • Design a SIS so that each SIF’s Achieved PFD is less than its Target PFD.
  • Lastly assign the selected Tests (with their tuned Test intervals) to the associated Equipment’s Schedules to ensure the SIFs achieve the target PFDs.