《风险评价技术及方法》 22._Cause–Consequence_Analysis.pdfVIP

Chapter 22 Cause–Consequence Analysis 22.1 INTRODUCTION Cause–consequence analysis (CCA) is an analysis methodology for identifying and evaluating the sequence of events resulting from the occurrence of an initiating event. CCA utilizes a visual logic tree structure known as a cause–consequence dia- gram (CCD). The objective of CCA is to determine whether the initiating event will develop into a serious mishap, or if the event is sufficiently controlled by the safety systems and procedures implemented in the system design. A CCA can result in many different possible outcomes from a single initiating event, and it provides the capability to obtain a probability for each outcome. The CCA technique is a method of risk assessment that provides a means of graphically displaying interrelationships between consequences and their causes. Safety design features that are intended to arrest accident sequences are accounted for in the CCA. 22.2 BACKGROUND This analysis technique falls under the system design hazard analysis type (SD-HAT). Refer to Chapter 3 for a discussion on hazard analysis types. The purpose of CCA is to identify and evaluate all of the possible outcomes that can result from an initiating event (IE). An IE is an event that starts an acci- dent sequence that may result in an undesirable consequence. Generally, there are Hazard Analysis Techniques for System Safety, by Clifton A. Ericson, II Copyright # 2005 John Wiley Sons, Inc. 383 384 CAUSE–CONSEQUENCE ANALYSIS many different outcomes possible from an IE, depending upon whether design safety systems work properly or malfunction when needed. CCA provides a pro