How can you track safety engineering requirements throughout the systems engineering process?

It's usually an attribute of the requirement that is defined in the requirements database It defaults to non safety when a requirement is created The issue is that you need to do a safety analysis of the system to identify what requirements are safety related The testing is also another issue as the probability of system failure is never zero

Systems-based approach to safety requires the application of scientific, technical and managerial skills to hazard identification, hazard analysis, and elimination, control, or management of hazards throughout the life cycle of a system, program, project or an activity or a product.

There are two types of safety requirements encountered during the project development. Functional safety requirements and Process safety requirements. Functional safety requirements are apportioned to specific requirements and specifications through system/subsystem/product levels. The functional safety requirements should be verified at each level of apportionment for traceability and validated during product testing, subsystem integration and system integration. Process safety requirements are better tracked by safety plans and demonstrated compliance through audits. Compliance to the safety requirements along with the risk assessment & acceptance of non-compliances form the basis of the safety argument in the safety case.

It is important to perform an early safety risk analysis so the identified hazards can be mitigated by implementing system safety requirements able to influence system design, which is usually a more cost-effective approach then adressing these hazards when the system is already constructed. These safety risks should be continuosly managed through the system’s life cycle following an approach similar to the one described by MIL-STD-882e “System Safety”.

Safety and Quality are integral to production, maintenance and servicing processes. A well defined safety guidelines and establishment of a responsible safety management organisation in the company is a must to avoid loss of life, injury, accidents and incidents. It should remain in the focus of management. Based on the nature of work the safety related tasks can be characterized by generic and task specific. Safety and Quality should be embedded in the employees and supervisors as a culture. Safety guidelines are to be clearly specified and compiled and are to be part of all process sheets.

Managing safety requirements involves system level safety analysis through various tools. After defining the safety goals (SIL or ASIL), safety requirements need to be added in requirement tool (DOORS, System Weaver, SE Tool or any RM tool) and should be clearly propagated to down the component level with requirement ID. Each component level Safety requirement should linked to the system / project level safety requirement in the tool.

Once system safety requirements are registered, they are managed just like any other system requirement. The use of a requirements management tool is recommended, especially if the quantity of requirements to be dealt with is significant. If no tool is available, make sure to use at least a spreadsheet to allow attributes (ID, author, rational, priority, etc.) to be associated with each individual requirement.

Manage Safety Requirements by allocating down to Components. Create Traceability to Design specs, then to Validation and Verification.

Manage safety requirements involves a systematic approach to ensure that safety measures are effectively implemented, monitored, and maintained throughout the project lifecycle. Project managers and safety professionals can effectively manage safety requirements and create a safe working environment for all project stakeholders. Consistent monitoring, communication, and continuous improvement are key to ensuring that safety remains a top priority throughout the whole project.

In the pursuit of safety, Design Engineers and Safety Engineers collaborate closely. Design Engineers translate safety requirements into design features, integrating safety from the outset. Safety Engineers oversee safety documentation, ensuring proper management and adherence to standards. Together, they uphold safety, implementing measures and documenting them meticulously, fostering a culture of safety excellence.

Monitor the progress against safety requirements throughout the design process. Use the requirements management tool or spreadsheet to track the status of each requirement and identify any issues or delays and validate.

Validating safety requirements is crucial for ensuring the effectiveness of safety measures. It involves rigorous testing, simulations, and analysis to verify that safety requirements adequately mitigate risks and uphold standards. Through meticulous validation processes, engineers can ensure that systems are robust and resilient, providing assurance that safety is prioritized and maintained throughout the project lifecycle.

As suggested by the standard, the functional safety validation is to ensure that the safety goal and the highest-level safety requirement has been met and is correct.

Validating safety engineering requirements against stakeholder needs and expectations is crucial for ensuring alignment and effectiveness. This involves verifying that safety requirements are not only relevant and achievable but also compliant with standards and regulations. Engaging stakeholders throughout the validation process fosters transparency and buy-in, enhancing the overall safety culture. Utilizing tools like safety reviews, audits, surveys, and validation tests enables thorough validation, promoting confidence in the safety measures implemented.

Validating safety requirements involves ensuring they align with stakeholder needs and comply with safety standards. It's crucial to confirm that requirements are relevant, realistic, and achievable. Engage stakeholders in validation, seeking their feedback and approval. Tools like safety reviews, audits, surveys, and validation tests are key for effective validation.

“Verify safety requirements” means another thing though. To verify something is to get evidence that it was done right. A system is verifyed by comparing it against system requirements. In the same manner, a requirement is verified when it fulfills the “requirements of a requirement”, i.e. the characteristics found on ISO/IEC/IEEE 29148.

Verifying safety requirements involves meticulous examination to confirm their accuracy and effectiveness. Engineers conduct thorough reviews, inspections, and analyses to ensure that safety measures align with established standards and regulations such as EN 50126,50128,50128,SiRF etc. By verifying safety requirements, engineers provide assurance that systems are designed and implemented to mitigate risks effectively, safeguarding lives and assets.

Verifying safety requirements entails ensuring the system meets these requirements through design and implementation, performing safely under all conditions. Documentation and evidence of verification are essential. Utilize safety testing, analysis, inspections, and verification reports for thorough verification.

It involves meticulous scrutiny to ensure effectiveness in mitigating risks. Engineers employ diverse methodologies, engage stakeholders, and embrace continuous improvement. By bridging theory with practice, evaluation ensures safety standards remain robust and reliable, safeguarding lives and assets effectively.

Evaluating safety requirements involves assessing their effectiveness, efficiency, and satisfaction against system performance and outcomes. This step identifies gaps, issues, and improvement opportunities, comparing actual vs. expected results. Tools for this evaluation include safety metrics, indicators, feedback, and evaluation reports.

To evaluate safety requirements thoroughly, it's essential to measure their impact on system performance and outcomes. Assess their effectiveness in mitigating risks and enhancing safety measures. Evaluate efficiency by considering resource utilization and cost-effectiveness. Additionally, gauge user satisfaction to ensure safety measures align with stakeholder expectations. Identify any gaps, issues, or opportunities for improvement through comprehensive analysis. Utilize tools such as safety metrics, indicators, feedback mechanisms, and evaluation reports to gather relevant data. By comparing actual results with expected outcomes, you can pinpoint areas needing attention and refine safety protocols accordingly.

To enhance safety requirements effectively, utilize evaluation findings and lessons learned to drive improvements. Implement corrective and preventive actions based on identified issues and areas for enhancement. Update safety requirements accordingly to reflect these improvements. Share best practices, lessons learned, and recommendations with stakeholders to inform future projects. Utilize tools like safety improvement plans, action items, lessons learned reports, and improvement reports to facilitate this process. By continuously refining safety protocols, organizations can bolster their safety measures and promote a culture of continuous improvement and resilience.

Improving safety requirements entails updating them based on evaluation findings and lessons learned. Implement corrective and preventive actions, share best practices, and disseminate recommendations. Tools include safety improvement plans, action items, lessons learned, and improvement reports.

Firstly, distinguish between safety managers and safety engineers as per standards to avoid system design conflicts. Safety isn't solely the domain of safety engineers; it requires a unified goal across all engineering disciplines. Every aspect, from coding to circuit design, testing, and even the tools and processes used in production, must prioritize safety. This necessitates basic safety engineering training for everyone involved, ensuring a comprehensive understanding at all levels. Crucially, senior leaders like SVPs and VPs must also take part in this training to bridge any potential gaps between leadership and operational levels. This holistic approach ensures that safety is embedded in the organization.

Two points 1) traceability - through the solution layers. For safety it’s important this is rigorous. And recognise the requirements sandwich - requirements for the lower layer elements are derived from the solution. Requirement trace from solution, not directly from other requirements 2) don’t fall into trap of worrying about safety requirements and rigorously managing them and ignoring the others. Do all requirements together, but with more rigour (see ARP4754A) for safety ones

In my experience with complex multi-layered designs, it is prudent to make the distinction between safety driving a design, and requirements resulting from e.g. an FMEA on that design. The top-level safety requirements are fixed (resulting from hazard analysis on baselined ODD and ConOps), but there may be more than one design solution fulfilling those safety requirements, and some solutions are more robust than others. Think about the outcome of an FMEA, having to add monitoring for certain identified failure modes. And these sets of requirements 'driving design' and 'derived through design' repeat each layer; outcome of one is input for the next. And the design on that layer is the rationale to progress to the next layer.

Some important points relating to safety risk management that in my experience can be often overlooked: 1. Applicable standards often dictate the safety risk management processes to follow - check these first. 2. Tailor the safety risk management process to match the system's complexity and associated hazards (complex systems should use comprehensive processes whilst simpler processes may be adequate for simpler systems). 3. Understand basic definitions such as 'hazard,' 'hazardous situation,' and 'risk' - this is vital, as is ensuring uniformity in their use across the team. 4. Implementing adequate traceability is critical for maintaining consistency and completeness over time across various interacting artifacts and processes.

Draw in a competent engineer into the role of functional safety manager. They will know what to do. Have them work alongside with the systems engineer and propagate their influence and responsibility across all domains and disciplines within the project