The purpose of the Modification phase of the Functional Safety Lifecycle is to ensure that any modifications of the SIS are adequately assessed and controlled.
Modifications of a Safety Instrumented Function should be properly planned, reviewed and approved prior to making the change. The safety integrity of the SIF must be maintained despite any changes made to the SIS.
An analysis must be carried to determine the impact on functional safety and is usually termed the Impact Assessment.
ProSalus has assisted clients in the developments of management of change procedures, impact assessments and post modification Functional Safety Assessment.