Integrating Safety into System Engineering

Previous chapters have provided the individual pieces of the solution to engineering a safer world. This chapter demonstrates how to put these pieces together to integrate safety into a system engineering process. No one process is being proposed Safety must be part of any system engineering process. 

This chapter starts with a discussion of the role of specifications and how systems theory can be used as the foundation for the specification of complex systems. Then an example of how to put the components together in system design and development is presented. Chapters 11 and 12 cover how to maximize learning from accidents and incidents and how to enforce safety constraints during operations. The design of safety information systems is discussed in chapter 13. 

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The next chapter describes how to integrate the disparate information and techniques provided so far in part III into a system-engineering process that integrates safety into the design process from the beginning, as suggested in chapter 6. 

Even today in the United States there are about 13 deaths daily in the workplace and 4 million injuries per year (Barab, 2012), which means we have to better integrate system safety into all engineering aspects. Studies conducted at Stanford University estimate the cost of accidents for nsers of conunercial and industrial construction at 1.6 billion annually. Hidden costs were found to be two to 18 times higher. Researchers also found that construction safety research over a 10-year period showed irrefutable... 

Facility System Safety (FSS), which is the application of system safety concepts to the facility acquisition process, has recently gained acceptance throughout the Department of Defense and most recently within the Department of Army with the conception of SAFEARMY 1990. The Army s goal is to fully integrate the total system safety, human factors, and health hazard assessments into continuous comprehensive evaluation of selected systems and facilities. The Chemical Research Development and Engineering Center (CRDEC) has mandated appropriate levels of system safety throughout the lifecycle of facility development for many reasons. These include ... 

There is no agreed upon best system engineering process and probably cannot be one—the process needs to match the specific problem and environment in which it is being used. What is described in part III of this book is how to integrate system safety into any reasonable system engineering process. Figure 6.1 shows the three major components of a cost-effective system safety process management, development, and operations. 

System safety and human factors integrated into the set of typical system engineering tasks. Standard verification and validation activities are not shown as they are assumed to be performed throughout the whole process, not just at the end where they are often concentrated. 

The danger inherent in this isolation of the safety efforts is argued repeatedly throughout this book. To be effective, the safety efforts must have impact, and they must be integrated into mainstream system engineering and operations. 

As we progress into the new century there are both opportunities and challenges. Qpportunities present themselves in the form of (1) the potential of integrating system software safety with control engineering to more closely achieve a level of intrinsic safety and (2) the proliferation of system safety as a discipline in other parts of the world. The challenges we face include the... 

In this three year period following on from the conceptual design, the system engineering for EFR was completed and the R D results were integrated into Ae design. Detailed studies concentrated on the analysis of crucial features of the design, on comprehensive assessments of the safety qjproach and the economic prospects. 

This places much emphasis on the engineering of sufficient safety integrity into the safety-related systems to ensure that risks affected by those systems are reduced to a level that is as low as reasonably practicable (ALARP). There are many methods and techniques for achieving this. The lEC standard 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems, for example, advocates a risk-based approach to determining the required safety performance of safety-related systems, and does so in the context of an overall safety life cycle. The success in the implementation of such an approach demands a suitable level of competence in the engineers involved in the determination of the safety requirements and in the realisation of such systems. 

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