We propose the combination of two established models of computation (X-machines and CCS) to
generate a new behavioural specification and modelling language, CCS-XM. We show that such a language
could be used to represent object-oriented systems, reason about their behavioural properties, and refine
specifications into designs which are correct-by-construction. We delineate some of the semantics of such a
language, and suggest areas where further research would be necessary.