SIL Verification

This workflow describes the process of verifying that the Safety Integrity Level (SIL) value for an Instrumented Function meets the target SIL defined in SIL assessment.

Blue text in a shape indicates that a description is provided for that step in the following sections. For more information, refer to the topic Interpreting the Workflow Diagrams.

Persona: Analyst

Determine if there is a Protective Instrument Loop (PIL) for the Instrumented Function. If one exists, redesign the loop based on the requirement. If one does not exist, define the PIL.

Persona: Analyst

Determine if there are sensors, logic solvers, and final elements in the PIL.

Persona: Analyst

After you identify the elements of the PIL, enter the details of each element in the corresponding record that is created when you create a PIL, such as the type, manufacturer, model number, and the failure rate.

Persona: Analyst

You can link a custom device or an element from SERH. This will populate the interfaces, modules, and channels for the element as needed. Alternatively, you can use the failure rate data provided by the manufacturer of the device, failure distributions, or other failure rate databases.

Persona: Analyst

After you select an element from SERH, the details of the element such as the mean time to repair and mission time are populated. Based on these values, the probability of failure, spurious trip limit, and other values are calculated. GE Digital APM then calculates the SIL value, spurious trip limit, and other values for the entire loop using the Markov calculation engine.

Persona: Analyst

Verify if the loop calculations meet the target SIL requirement specified in SIL Assessment.

Persona: Analyst

You can modify the proof test intervals of each element to ensure that the SIL value meets the target SIL value. You can manage proof testing in SIL Validation.

Persona: Analyst

Go to the SIL Validation workflow.

Persona: Analyst

Elements with better failure rates can be substituted or additional elements can be added in voted scenarios to improve performance.

Persona: Analyst

Go to the SIL Assessment workflow.

Persona: Analyst

Go to the Custom Device workflow.