A Simple Toy Example of a Distributed System On the Design of a Connecting Switch

In this paper the development life cycle of a design method for distributed systems is ex plained in close connection with the example of the connecting switch A connecting switch is a system where stations may get connected may then send actions and may get disconnected it exhibits the behaviour of a very simple protocol A development life cycle commonly includes four phases requirement speci cation design speci cation abstract program design concrete program design This requires collecting various description formalisms into one design method Each transition of one phase to a more concrete one is guided by a design decision each veri cation of the corresponding transition result remains as proof obligation By the case study of a connecting switch the application of the design method will be demon strated by treating this example within all four phases in order to make the design method more transparent