Risk Assessment, 2nd Edition

Chapter 3 Main Elements of Risk Assessment

3.1 Introduction

The terms “risk analysis” and “risk assessment” are used several times in Chapters 1 and 2 without any proper definition. We define the terms as follows:

Definition 3.1 (Risk analysis)

A systematic study to identify and describe what can go wrong and what the causes, the likelihoods, and the consequences might be.

A risk analysis is, according to Definition 3.1 , aimed at providing answers to the three questions used to define risk.

Definition 3.2 (Risk assessment)

The process of planning, preparing, performing, and reporting a risk analysis, and evaluating the results against risk acceptance criteria.

Figure 3.1 Risk assessment as a combination of risk analysis and risk evaluation.

In addition to planning, preparing, and reporting, risk assessment consists of two main analytical parts: risk analysis and risk evaluation, as shown in Figure 3.1 . First, a risk analysis is carried out to identify and describe relevant accident scenarios and likelihoods, which together, define the risk. The second part, risk evaluation, compares the risk determined by the risk analysis with risk acceptance criteria, as discussed in Chapter 5.

3.1.1 The Role of the Risk Analyst

The main role of the risk analyst is to answer the three questions in the definition of risk in Section 2.2.1 , and to ...