THE ISO REFERENCE MODEL FOR OPEN DISTRIBUTED-PROCESSING - AN INTRODUCTION

The ISO Reference Model of Open Distributed Processing (RM-ODP) consis ts of four parts: an Overview of the reference model, the Descriptive Model, the Prescriptive Model, and the Architectural Semantics. The fo ur parts provide the concepts and rules of distributed processing to e nsure openness between interacting distributed application components. Openness is a combination of characteristics: i.e. scalability, acces sibility, heterogeneity, autonomy and distribution. The RM-ODP introdu ces the concept of viewpoint to describe a system from a particular se t of concerns, and hence to deal with the complexity of distributed sy stems, While all the viewpoints are relevant to the description and de sign of distributed systems, the computational and engineering models are the ones that bear most directly on the design and implementation of distributed systems. From a distributed software engineering point of view, the computational and engineering viewpoints are again the mo st important; they reflect the software structure of the distributed a pplication most closely. In this introductory paper, we concentrate on the computational and engineering viewpoints.