This paper motivates the need for a formalism for the modelling and analysis of dynamic reconfiguration of dependable real-time systems. We present requirements that the formalism must meet, and use these to evaluate well-established formalisms and two process algebras that we have been developing, namely, Webπ _∞ and CCS ^dp . A simple case study is developed to illustrate the modelling power of these two formalisms. The paper shows how Webπ _∞ and CCS ^dp represent a significant step forward in modelling adaptive and dependable real-time systems.