This document describes a framework for functional safety to enable the use of pre-existing software architectural elements not originally developed in accordance with the ISO 26262:2018 series, but intended to be integrated into safety-related embedded software conformant with the ISO 26262:2018 series by:

• determining relevant criteria when using the pre-existing software architectural element as a safety-related element of safety-related embedded software;
• determining relevant criteria inherent to the pre-existing software architectural element, e.g. needs for external safety mechanisms to detect and control failures caused by the pre-existing software architectural element;
• providing suitable evidence and arguments for use of the pre-existing software architectural element that can include applicable procedures, techniques and safety measures;
• supporting the fulfilment of software safety requirements when using the pre-existing software architectural element as a safety-related element of safety-related embedded software;
• supporting the integration of the pre-existing software architectural element as a safety-related element of safety-related embedded software.