High speed circuits and systems in their vast majority are still invariably based on CMOS technology for obvious cost and power efficiency reasons. Photonics science is gaining momentum in these high speed systems and is traditionally found in telecommunications but also in high performance computing and recently in standard computing systems with the main objective of alleviating the CPU to memory bottleneck. RF processing is producing another level of complexity in the new emerging variety of embedded mixed-signals circuits and systems where a signal changes its media types several times without leaving the package assembly. This new paradigm where RF, analogue, digital and optical signals are integrated in one component entails an ad-hoc testing and hierarchical fault modelling approaches that embrace the individual approaches of each of these signal types and amalgamate them into one optimised approach.