Understanding Safety-Critical Systems: A Balancing Act

Safety-critical systems are designed to minimize the risks to health and safety as much as reasonably practicable. This concept emphasizes the importance of making informed decisions about the trade-offs between safety benefits and the costs of implementing those safety measures. The idea of residual risk—elements that are unavoidable and thus tolerable—plays a key role in determining what further mitigations, if any, are necessary.

The Occupational Safety and Health Administration (OSHA) took a significant step in 1992 by publishing a process safety standard specifically for hazardous materials. This standard is a prime example of how system safety techniques from various industries can be adapted for use in the chemical sector. This approach stands in contrast to traditional safety regulations, which have often been reactive and prescriptive, emerging primarily in response to specific accidents or incidents.

One notable illustration of the limitations of earlier safety approaches is the Reactor Safety Study WASH-1400, published in 1975. While it accurately identified potential failure scenarios for nuclear reactors, it underestimated the probability of human error, a critical oversight that became evident during the Three Mile Island incident in 1979. Such historical lessons underscore the need for continuous improvement in safety practices across all sectors.

Even relatively young nations are making strides in safety regulation. The United Arab Emirates, established in 1971, has made significant advancements in this area. In 2010, Abu Dhabi launched the Environment, Health, and Safety Center, which initiated the development of comprehensive safety standards across various industries, including transportation, health, and construction. This proactive approach reflects a broader trend where countries recognize the necessity of implementing stringent safety practices to protect their citizens.

The evolution of the system safety engineering profession is largely driven by the imperative to reduce unacceptable levels of accidents, fatalities, and economic losses. Engineers are increasingly compelled to integrate safety into the design of systems and products, reflecting a growing acknowledgment of the complexities involved in ensuring safety within various industries. Through ongoing education and adaptation, the profession continues to evolve in response to emerging challenges and technologies.