ABSTRACT
There are many techniques to evaluate risk. In fact, the methodologies and specific tools vary as much as the organizations that use them. In this chapter, we will introduce some of the most common ones. Risk analysis methodologies fundamentally fall into three categories:
1. Qualitative methodologies a. Preliminary risk analysis b. Hazard and operability (HAZOP) studies c. Failure mode and effects analysis (FMEA); failure mode and
effects criticality analysis (FMECA) 2. Tree-based techniques a. Fault tree analysis b. Event tree analysis c. Cause-consequence analysis d. Management oversight risk tree e. Safety management organization review 3. Techniques for dynamic systems a. Go method b. Digraph or fault graph c. Markov modeling d. Dynamic event logic analytical methodology e. Dynamic event tree analysis
Preliminary Risk Analysis
Preliminary risk or hazard analysis is a qualitative technique involving a disciplined analysis of event sequences that could transform a potential hazard into an accident. The possible undesirable events are identified first
and then analyzed separately. For each undesirable event or hazard, possible improvements or preventive measures are formulated.
