Assurance of the system reliability of a gearbox considering prior knowledge

Abstract

System reliability is predicted for the EcoLife 6-gear automatic transmission from ZF Friedrichshafen AG taking various calculations and testing procedures during product development into account at different system levels. The system reliability predicted in this way is compared to the field reliability derived from the actually observed failure behaviour. The combination of methods as developed, applied and validated in this paper aids in streamlining reliability efforts due to the fact that an updateable process of determining reliabilities at various system levels is formed.