These Proceedings report the scientific results of the Summer Study on Plural Rationality and Interactive Decision Processes orga nized jointly by the System and Decision Sciences Program of the Inter national Institute for Applied Systems Analysis (located in Laxenburg, Austria) and the Hungarian Committee for Applied Systems Analysis. The Study, which was held in Sopron over the period 16-26 Augus·t 1984, had a very special character. Sixty-eight researchers from sixteen coun tr~es participated, most of them contributing papers or experiments. In addition many members of IIASA's Young Scientists Summer Program were present. All of these participants were heavily involved in dis cussions; discussions that were not limited to the allotted time but extended well into the evenings and nights. By design, the Study gathered specialists from many disciplines, from philosophy and cultur al anthropology, through decision theory, game theory and economics, to engineering and applied mathematics. A further element of diversity was the representation of several varieties of culture, from typically Western countries, through Middle and Eastern Europe, to the Far East.

These Proceedings report the scientific results of an International Workshop on Methodology and Software for Interactive Decision Support organized jointly by the System and Decision Sciences Program of the International Institute for Applied Sys tems Analysis (nASA, located in Laxenburg, Austria) and The National Committee for Applied Systems Analysis and Management in Bulgaria. Several other Bulgarian institutions sponsored the Workshop - The Committee for Science to the Council of Ministers, The State Committee for Research and Technology and The Bulgarian In dustrial Association. The workshop was held in Albena, on the Black Sea coast. More than 80 scientists from 15 countries attended the workshop; 50 lectures were presented and 17 computer demonstration sessions took place. This Workshop is one of a series of meetings organized by nASA with the collaboration of scientific institutions from the National Member Organization countries. The previous meetings took place in Austria (1983), Hungary (1984) and the German Democratic Republic (1985). All proceedings of these meetings have been published by Springer Verlag in the series Lecture Notes in Economics and Mathematical Systems.

The book aims at giving the methodological framework for design decision support systems. Several applications are also described in detail, ranging from environment control, production planning, transportation planning. The book is of special interest to operations researchers, environment specialists, production planners, and transportation engineers.

These Proceedings report the scientific results of an International Workshop on Large-Scale Modelling and Interactive Decision Analysis organized Jointly by the System and Decision Sciences Program of the International Institute for Applied Systems Analysis (IIASA, located in Laxenburg, Austria), and the Institute for Informatics of the Academy of Sciences of the GDR (located in Berlin, GDR). The Workshop was held at a historically well-known place - the Wartburg Castl- near Eisenach (GDR). (Here Martin Luther translated the Bible into German.) More than fifty scientists representing thirteen countries participated. This Workshop is one of a series of meetings organizE!d by or In collaboration with IIASA about which two of the Lecture Notes In Economics and Mathematical Systems have already reported (Voi. 229 and Vol. 246). This time the aim of the meeting was to discuss methodological and practical problems associated with the modelling of large-scale systems and new approaches In interactive decision analysis based on advanced information processing systems.

In the past, technological as well as economic forces dominated the evolution of industrial structures: these factors have been treated extensively in numerous studies. However, another major factor which has begun to have a decisive influ ence on the performance of the chemical industry is technological risk and public and environmental health considerations, in particular those related to toxic and hazardous substances used in industrial production processes. The issues of con trolling process risk, waste streams, and potential environmental consequences of accidental or routine release of hazardous chemicals are rapidly gaining in impor tance vis CI vis narrow economic considerations, and are increasingly reflected in national and international legislation. In the context of several ongoing R&D projects aiming at the development of a new generation of tools for "intelligent" decision support, two related problem areas that have been identified are: (i) Structuring the industry or plant for the minimum cost of production as well as least risk - e.g., toxicity of chemicals involved. In this multi-criteria framework, we seek to resolve the conflict between industrial structure or plant design established by economic considerations and the one shaped by environmental concerns. This can be formulated as a design problem for nor mal production conditions. In section 3.1. and 3.2. an approach on how to deal with this problem at the industry and plant level is discussed.