In general there are 3 key stages:
- IEC 61511 Lifecycle Stage 2: Once your Hazard studies and Risk Assessments are complete (e.g. HAZOP LOPA) and the next stage is to complete the design of the Safety Instrumented Functions (SIFs)
- IEC 61511 Lifecycle Stage 3: As per the Safety Requirements Specification (SRS) a FSA will need to be conducted before any introductions to the hazards of the process system.
- IEC 61511 Lifecycle Stage 4: During the life cycle of a plant or process system, sufficient data will be generated and captured in order to assess the original assumptions, their validation, or whether they require updating to reflect operational experience. In order to ensure your safety system operating methodology and philosophy is current and up to date, this should be completed periodically.