SIL Verification

SIS Management: SIL Verification Workflow

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.

In the following workflow diagram, the blue text in a shape indicates that the corresponding description has been provided in the sections that follow the diagram. For more information, refer to the Interpreting the Workflow Diagrams topic in the APM Product Workflows documentation.
Note: For information on the personas associated with a APM module, refer to the APM Product Workflows documentation.
Define/Re-design PILDefine PIL ElementsVerify PIL Calculation ResultsSIL VerificationUse an SERH Device or a Custom DevicePIL Results CalculatedModify Test IntervalAbout Exida Project FilesSIL ValidationCustom Device

Define/Re-design PIL

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.

PIL Elements Defined?

Persona: Analyst

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

Define PIL Elements

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.

Use an SERH Device or a Custom Device

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.

PIL Results Calculated

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. APM then calculates the SIL value, spurious trip limit, and other values for the entire loop using the Markov calculation engine.

Verify PIL Calculation Results

Persona: Analyst

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

Modify Test Interval

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.

Modify PIL Design

Persona: Analyst

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