PCL: A language for modelling evolving system architectures

The paper describes a language called PCL, which has been designed to model the architecture of multiple versions of computer-based systems (system families), PCL has evolved from module interconnection languages, and its novel features include the ability to model the variability between members of a system family and facilities for the integrated modelling of hardware, software and documentation structures, The features of PCL are illustrated using a number of simple examples. A supporting toolset for PCL has been implemented and is briefly described.