Inductive and Deductive Reasoning: The Case of Identifying Potential Hazards in Chemical Processes

This chapter presents a new approach to hazard analysis and assessment, one that begins with the inductive determination of hazardous chemical or physical reactions and proceeds deductively through the network of processing steps to identify completely all causes initiating these hazardous reactions. This strategy is more efficient in the identification of reaction-based hazards than conventional methodologies. The approach ensures completeness and resolves uncertainty of design quality through first principles-based quantification of the design risk. Moreover, it enables a computer-aided automation. Regardless of what stage the design is in, a designer's attention can be focused at (1) earlier design stages and their vulnerable areas so that the associated hazards can be eliminated or (2) later stages, where the a priori sequence of events that leads to hazards can be used as an early warning structure. The methodology employs domain-specific modeling languages to describe (1) chemicals and their reactivity during the inductive identification of potential reaction-based hazards, and (2) processes during the deductive identification of their process-based causes. The fundamental premise in all of the approaches that attempt to mitigate or control hazards lies on the assumption that they have the ability to both identify accurately and pinpoint precisely the location of a potential future hazard. The chapter shows that although understanding the set of enabling conditions is essential for safe plant operation, the identification of the entire set of enabling conditions is an intractable task.