A Formal Treatment of Distributed Systems Design

The paper reports on a technique for the formal definition of the distributed systems design methodology called the Total System Design (TSD) Methodology. Central to the formalization of the TSD Methodology is the TSD Model, which consists of several information structures and a set of consistency constraints (i.e., acceptance criteria). While the major part of this paper is taken by the model definition, the authors\u27 intent is not simply to justify the model itself. The paper provides convincing evidence that rigorous methodology definitions are both feasible and useful. It offers examples of how to approach the formalization of various methodological concepts such as satisfiability of system requirements, hierarchical structuring of the system, and stepwise refinement. Finally, it shows how these and other concepts of practical value in distributed systems design may become better understood through the use of the proposed formalizations