ABSTRACT
Technical systems are affected by many different stress factors during their usage. Due to the unequal usage behaviour of different groups of users not every subsystem in a complex system is used and stressed in an identical way. These differences cause a relevant effect on the reliability of a system. In application to the automotive industry for example, the usage of the braking system between infrequent to frequent drivers is very different. In this case, infrequent drivers use the braking system per kilometre more often than frequent drivers. This is founded on the matter of fact, that infrequent drivers have a higher percentage in city rides (with many brakings) than frequent drivers. This causes higher stress to the braking system, with the effect of more failures in fewer kilometres independent from the lifetime. Common reliability analyses do not consider this important task.
