Cause-Consequence Analysis

Cause-consequence analysis uses symbolic logic trees similar to fault trees. You start with an accident or failure scenario that challenges or adversely impacts the system and then develop a bottom-up analysis. Failure probabilities are calculated and incorporated into each step of the analysis, and thus quantify the tree. 

A fault tree can be used to arrive at the event that challenges the system. The probability of occurrence is included here. From that top event, the consequences are 

System Safety Engineering and Risk Assessment A Practical Approach 

Cause-consequence risk e aluation combines event tree and ult tree analysis to relate specific accident consequences to causes. The iHOcess of cause-consequence evaluation usually proceeds as follows  

Describe the safety system(s)/procedure(s)/factor(s) tliat interfere witli tlie patli of the accident 

Perform an event tree analysis to find tlie path(s) an accident may follow 

Perform a fault tree analysis to determine tlie safety function tliat failed 

Rank tlie results on a basis of severity of consequences 

---

As its ntune implies, cause-consequence analysis allows one to see how the possible causes of an accident and tire possible consequences tliat result from that event interact witli each other. 

Section 18.2 Risk Cliaracterization Section 18.3 Cause-Consequence Analysis Section 18.4 Qualitative Hazard Risk Analysis Section 18.5 Quantitative Hazard Risk Analysis Section 18.6 Uncertainties/Limihitions Section 18.7 Public Perception of Risk Section 18.8 Risk Communication... 

Cause-consequence analysis serves to characterize the physical effects resulting from a specific incident and tlie impact of these physical effects on people, tlie environment, and property (causes are discussed tluoughout Cliapter 16). Some consequence models or equations (see Chapter 17) used to estimate the potential for dniiuige or injury fall into several categories. ... 

In a more quantitative sense, cause-consequence analysis may be viewed as a blend of fault tree end event tree analysis (discussed in tlie two preceding cliapters) for evaluating potential accidents. A major strengtli of cause-consequence analysis is its use as a communication tool. For example, a cause-consequence diagram displays the interrelationships between tlie accident outcomes (consequences) and Uieir basic causes. The method can be used to quantify the expected frequency of occurrence of the consequences if the appropriate chita are available. 

Logic Diagram Methods (Fault Tree Analysis, Event Tree Analysis, Cause-Consequence Analysis, Human Reliability Analysis, Success and Failure Trees, etc,)... 

Three hazard evaluation procedures using logic diagrams are (1) fault-tree analysis (FTA), (2) event-tree analysis (ETA), and (3) cause-consequence analysis (CCA). Appropriate references are [2,3,251,261]. 

Three hazard analysis techniques are currently used widely Fault Tree Analysis, Event Tree Analysis, and HAZOP. Variants that combine aspects of these three techniques, such as Cause-Consequence Analysis (combining top-down fault trees and forward analysis Event Trees) and Bowtie Analysis (combining forward and backward chaining techniques) are also sometimes used. Safeware and other basic textbooks contain more information about these techniques for those unfamiliar with them. FMEA (Failure Modes and Effects Analysis) is sometimes used as a hazard analysis technique, but it is a bottom-up reliability analysis technique and has very limited applicability for safety analysis. 

Making Component Failure Probability Estimates Combinatorial Failure Probability Analysis Using MIL-STD-882 Event Tree Analysis Cause-Consequence Analysis... 

A quantitative risk review technique. Cause-consequence analysis is a hlend of fault tree and event tree analysis. This technique combines cause analysis (described by fault trees) and consequence analysis (described by event trees), and hence deductive and inductive analysis is used. The purpose of CCA is to identify chains of events that can result in undesirable consequences. With the probabilities of the various events in the CCA diagram, the probabilities of the various consequences can be calculated, thus establishing the risk level of the system. See also Event Tree Analysis (ETA) Fault Tree Analysis (FTA). 

---