  The nature of Systems of Systems (SoSs), large complex systems composed of
independent, geographically distributed and continuously evolving constituent
systems, means that faults are unavoidable. Previous work on defining
contractual specifications of the constituent systems of SoSs does not provide
any explicit consideration for faults. In this paper we address that gap by
extending an existing pattern for modelling contracts with fault modelling
concepts. The proposed extensions are introduced with respect to an Audio
Visual SoS case study from Bang and Olufsen, before discussing how they relate
to previous work on modelling faults in SoSs.
