Field data reliability analysis of highly reliable item

In recent years the effect of electronic elements has become more and more significant in many areas of human activity. Automotive engineering is one of the areas which have been also importantly affected. Electronic elements, processors and other information technology items are implemented there to a great extent. It is hard to imagine nowadays that a brand new system would not have the electronic elements. The paper deals with dependability namely reliability analysis procedure of a highly reliable item. We always believe that such items are reliable enough to fulfil our requirements regard-ing the system operation. Sometimes it may happen that such device does not control comfort electronics only. From this point of view possible failure might have significant effect onto humans ’ lives, property damages and the environment. The data on manufacturing and oper-ating of a few hundred thousands pieces of this device are available and it is statistically a very important collection/set. However, concerning some items the manufacturing procedure was not checked and controlled accurately. It is a case of software during manufacturing which is more the area of software dependability. This manufacturing inaccuracy might be manifested notably in availability and safety of a certain system subsystem. The failure/error manifesta-tion might be observed both during operating and downtime. The procedure described in the paper is based on the thorough data analysis aiming at the operating and manufacturing of these electronic elements. The results indicate some behaviour differences between correctly and incorrectly made elements. It was proved by the analysis that dependability and safety of these elements was affected to a certain degree. Although there is a quite big set of data the issue regarding the statistical comparability is very important.