1. Safety Integrity Level (SIL) Classification

2. SIL Classification 5

3. 5 Classes of demand ( D)
D0: negligible demand rate; the scenario has not been heard of in industry;
D1: the interval between demands is more than 20 years; the scenario is unlikely to occur during the lifetime of the platform, but has been heard of in industry;
D2: the interval between demands is 4 to 20 years; the scenario is likely to occur during the lifetime of the platform or has already occurred before in the platform;
D3: the interval between demands is 6 months to 4 years; the scenario is likely to occur in the time period between two major stops;
D4: the interval between demands is less than 6 months; the scenario occurs several times per year on the platform

4. Risk Matrix to Determine Personal SIL Level5

5. Risk Matrix to Determine Economic SIL Level5

6. Risk Matrix to Determine Environmental SIL Level5