Expressing requirements on a parallel system formally

We examine the nature of requirements on parallel total systems and the problem of documenting those requirements formally. The choice of the formal description method to be used should take into account the nature of the system to be developed and the benefits that method will bring to the provision of requirements in that particular project. We present our discussion through a case study of a formal description of an industrial-scale parallel system. Various project criteria for the formal documentation of requirements yield a method of formal description where the semantics of the language representing the system is given by first specifying the semantics of a quotient language and then extending to the original language by equational reasoning. We formulate the general method and indicate which types of project might adopt a similar approach. © 1996 Springer-Verlag London Limited.