Risk Assessment: Tools, Techniques, and Their Applications

1.2 Performing Risk Assessments

There is no absolute rule as to how a risk assessment should be performed and to what depth it should be performed. The NASA PRA guide (14) provides some recommendations and the Nuclear Regulatory Commission (NRC) provides numerous guideline documents on the topic (15). The Occupational Safety and Health Administration's (OSHA) “Process Safety Management of Highly Hazardous Chemicals” regulation (29CFR1910.119) (16) requires hazard analyses be performed for certain types of chemical operations, and the Department of Energy (DOE) specifies risk assessments for certain types of facilities (17). However, it is still up to the organization to decide how in depth the analysis should be. This book discusses tools that are effective for performing risk assessments, but the decision as to when to use the tools is up to the risk analyst. Table 1.1 provides a list of the risk assessment tools discussed in this book and at what point in an analysis they are traditionally used. In addition, this book provides other techniques that can be used to enhance a risk assessment, such as task analysis for determining human actions in a process, the Delphi process for eliciting human error probabilities, and the critical incident technique for developing risk scenarios.

Table 1.1 Risk Assessment Tools

Tool	Traditional use	Book chapter
Preliminary hazard analysis (PHA)	This tool is used in the very beginning of a risk assessment and/or on a conceptual design of a ...