Up to now, the reliability achieved by COTS components was largely sufficient for avionics, in terms of failure rate as well as time to failure. With the implementation of new and more integrated technologies (90 nm node, 65 nm and below), the question has arisen of the impact of the new technologies on reliability. It has been stated that the lifetime of these new technologies might decrease. The drift is expected to be technology dependent: integration, technology node, materials, elementary structure choices and process pay a key role. Figures have been published, which gives smaller lifetime than the 30 years generally required for avionics. This would of course impact not only the reliability, but also the maintenance of COTS-based avionics. Hence a new policy should be defined for the whole COTS supply chain. Faced with these impending risks, different methodologies have been developed. As far as EADS is concerned, we launched a study based on a Physics-of-Failure approach to assess the risks linked to the use of these technologies. Reliability may only be assessed if the end-user describes his mission profile, in which the COTS will be deployed. This is not enough: the COTS technology should be known in detail to choose the relevant parameters for the degradation models of the failure mechanisms, which are both possible and relevant in this usage environment. This paper presents the methodology with relevant simulation and experiments, supported by an application case.