2) Identify previously unidentified safety hazards associated with the design of sub-systems. 

a) The implementation of sub-system design requirements and mitigation measures must not introduce any new safety hazards to the system. The PO must determine potential safety hazards resulting from modes of failure, including: 

• Component failure modes and human errors, 

• Single-point and common cause failures, 

• The effects when failures occur in sub-system components, and 

• The effects from functional relationships between components and equipment comprising each sub-system. Consider the potential contribution of sub-system hardware and software events, faults, and occurrences (such as improper timing). 

3) Recommend necessary actions to eliminate previously unidentified hazards or mitigate their associated risks. 

a) Determine risk and the need for additional safety requirements to mitigate operational hazards. Develop system safety requirements to assist in preparing performance and design specifications. 

b) Ensure system-level hazards attributed to the sub-system are analyzed and that adequate mitigations are identified for possible implementation in the design as directed by the government. 

4) Establish the framework for follow-up hazard analyses that may be required. 

## 3.3 Software Aspects of Analysis 

Software guidance may be reviewed in the following sections of the Safety Risk Management Guidance for System Acquisitions: 

• Section 2.3.2.1.4, System Development Assurance (for the Investment Analysis Readiness Decision); 

• Section 2.3.3.1.2.1, System Development Assurance (for the Initial Investment Decision); 

• Section 2.3.4.1.2.1, System Development Assurance (for the Final Investment Decision); 

• Section 2.3.5.1.3, System Development Assurance (for the ISD); 

• Section 6.3, Managing Software Risk; 

• Section 9.4, Software-Intensive Systems; 

• Appendix A, Guidance for Preparing and Implementing Program Safety Plans, Section 5.1.3, Identify Developmental Assurance Requirements; and 

• Appendix M, Overview of RTCA DO-278A and Its Required Deliverables. 

The Development Assurance Level (DAL) is based on hazards identified during the SRM process. Until this point, the SRM process was conducted without any specific details about 

