The main role of the University of Exeter in the PHOENICS project will be to provide specialist expertise for the modelling of phase-change materials, devices and systems. Such modelling will play a significant part in WP4 and WP6, where it will aid significantly in the understanding of device and system performance and, importantly, enable the proper design and optimisation of materials, devices and systems. UNEXE has vast experience in the development and application of suitable models, having, for example, pioneered the use of rate-equation and cellular automata methods for physically realistic simulation of phase-switching processes in electrical and photonic phase-change devices. We have also developed more computationally-efficient behavioural models that can capture the essential outputs of the physically-realistic models, and are thus more suited to the understanding and design of system level (as opposed to device level) performance. All such models will be extended and adapted in the PHOENICS project to enable the modelling of phase-change based matrix multiplier devices and systems developed in WP4, and the various analog computation applications of WP6.