A new approach to modelling distributed systems is presented. It uses sequential processes and event synchronization as building blocks to construct a cohesive picture of the interdependent requirements for the functionality, architecture, scheduling policies, and performance attributes of a distributed system. A language called CSPS (an extension of Hoare\u27s CSP) is used in the illustration of the approach. Employing CSP as a base allows modelled systems to be verified using techniques already developed for verifying CSP programs and leads to the emergence of a uniform incremental strategy for verifying both logical and performance properties of distributed systems. Several small distributed systems have been modelled using this approach. These exercises enabled us to evaluate the notation system and to gain some expertise on how to approach the specification of distributed systems. This paper describes one of the models and the modelling strategy that has emerged from these exercises
