Mistakes to avoid
Aggregation of hazardous phenomena

When analyzing the loss of containment of a pipe, it is not permitted to split it into several fictitious sections in order to reduce the probability of occurrence of hazardous phenomena. For example, a pipe of length L with a Class D leak frequency cannot be split into two Class E sections. On the other hand, if only one section of pipe is likely to lead to a level of severity, then two different accidents can be presented. The former sheet no. 6 of December 28, 2006 "Pipe leaks: representation and rating" (included in the circular of May 10, 2010) gives an example of application.