In order to gain an improvement of safety or availability measures of the safety-relevant control system through employment of redundancy a redundant system has to comply with the requirement Trailer Hitch on independence of redundant parts.If the requirements on the independence of redundant parts are unfulfilled, then a common-cause failure can directly cause a hazardous state on a system level through its effects on multiple redundant parts.Identification of sources and quantification of the common-cause failure parameters has been proved to be a formidable task.
The latter problem, including other major safety-affecting factors lays in the focus of this paper.Our proposed technical safety analysis concept is JADE PEARL RICE RAMEN extended, so now it partially covers elusive problems related to the common-cause failures.