%A M. Makowski %T Design and Implementation of Model-based Decision Support Systems %X Decision making often requires the analysis of large amount of data and complex relations. Computerized tools designed and implemented for such purposes are called Decision Support Systems (DSS). A DSS, which is typically a problem specific tool, usually helps in the evaluation of consequences of given decisions and may advise what decision would be the best for achieving a given set of goals. In such cases, an analysis of a mathematical model can support rational decision making. The paper provides an overview of the methodology of the design and deals with practical aspects related to implementations of model-based decision support systems. In particular, different approaches to the analysis of a model using simulation and optimization are summarized. Various optimization techniques are discussed in this context, including multi-criteria optimization used for a model analysis. The paper summarizes also problems of hardware selection and of software development. Modular software tools applicable to DSSs, including a tool for data interchange, are characterized. Selected issues of implementations of modular solvers and of applications of artificial neural nets to decision support are also presented. %C IIASA, Laxenburg, Austria %D 1994 %I WP-94-086 %L iiasa4125