Formal Speciication of Distributed Information Systems

The design of distributed information systems tends to be complex and therefore error-prone. However, in the eld of monolithic, i.e. non-distributed, information systems much has already been achieved, and by now, the principles of their design seem to be fairly well-understood. The past decade has shown also remarkable progress in the development and application of formal methods for distributed systems , in particular in the area of protocol systems. For both application areas techniques and tools have been developed that have been accepted by considerable user communities. The project we describe here aims to study the combination of two formalisms that have been (largely) developed at the University of Twente, viz. the process algebraic protocol speciication language LOTOS and the object-oriented database speciication language TM. Its objective is to combine the strengths of both formalisms and their associated tools for the speciication, veriication, testing, and design of distributed information systems. Speciication of distributed information systems appears to be too complex to deal with on a mere intuitive basis. The TM/LOTOS integration project aims at formal speciication of such systems. The two main objectives of this paper are: to outline the TM/LOTOS project and compare it to other approaches, and to present several ideas and a few results in more detail. We state the objectives and context of this project in section 1. Afterwards we present the main characteristics of LOTOS and TM. Then, in section 2, we discuss the scientiic relevance of this project, and compare it to a number of other approaches. Finally, in section 3, we present a few results and some ideas for further research.