- “Design for Safety” is a systematic approach aiming to minimize accidents during a system’s lifecycle.
- It had a significant evolution in the 1950s due to the Air Force’s need for efficient aircraft design.
- Implementing safety in the early design stages is more cost-effective and efficient.
- Using “intrinsic safety” as a guiding principle ensures that the system’s safety is innate and not compromised.
- There are eight golden rules for a design for safety strategy, underpinned by conservatism.
The Genesis of “Design for Safety”
Modern engineering and design are more than just creating efficient systems. They also encompass the critical objective of ensuring safety. “Design for Safety” is the embodiment of integrating safety principles in all phases of a system’s lifecycle, from conceptualization to decommissioning.
Its inception can be traced back to the 1950s when the US Air Force realized that mere trial and error weren’t enough for aircraft design. This period marked the introduction of the MIL-STD-882 standard, which remains relevant even today.
Pillars of Safety: Three Foundational Principles
1. Safety From the Get-Go
Every engineer or designer knows that it’s easier to adjust designs in the early stages. Thus, it’s essential to introduce hazard identification early. The earlier potential security weaknesses are identified, the more economical and feasible the modifications become.
2. The Lessons of Yesterday
It’s paramount to learn from the past. By reviewing past design deficiencies and ensuring they don’t recur, the design process becomes more refined and foolproof.
3. A Symbiotic Relationship
Safety doesn’t exist in a vacuum. It needs to integrate seamlessly with other disciplines, all while contributing to the project’s overall goals. This requires a blend of engineering techniques and management strategies.
The Gold Standard: Intrinsic Safety
Perhaps the most coveted achievement in “Design for Safety” is achieving intrinsic safety. This principle ensures that the safety measures belong intrinsically to the system, making them virtually immune to unwanted events. It’s the design equivalent of ensuring that even if things go haywire, the system remains fail-safe.
Instead of managing potential hazards, designers should think about excluding them altogether, embodying the very ethos of intrinsic safety.
The Eight Golden Rules
The road to designing for safety can be paved by adhering to these eight golden rules:
- Minimize: Reduce hazardous materials and interfaces. Simplicity is key.
- Simplify: A straightforward system is more analyzable and less prone to risks.
- Error Tolerance: Design systems robust enough to handle unforeseen failures or deviations.
- Limit Effects: Oversize the equipment to ensure it never operates at its absolute limit.
- Trust in the Tested: New technology, while tempting, brings new uncertainties.
- Silent Systems: Systems should be independent, avoiding triggering cascading failures.
- Human-Centric Design: Making systems human-friendly minimizes the risk of human errors.
- Rigorous Monitoring: Regular inspections ensure that the design remains as intended over time.
The Ultimate Philosophy: Conservatism
While these golden rules are diverse, they share a core philosophy: conservatism. This is not about resisting change but rather about introducing changes incrementally. It promotes using proven components over untested ones and, fundamentally, prioritizes the intensive use of industry standards and best practices.
In essence, “Design for Safety” is a philosophy that should be deeply ingrained in every engineering and design endeavor. With the stakes as high as human lives and vast investments, there’s no room for compromises. Safety isn’t just a requirement—it’s a responsibility.