This collection of articles is on Decision Support Systems (DDS), Group Deci sion Support Systems (GDSS), Executive Information Systems (EIS) and Expert Systems (ES), which presents a solid conceptual-theoretical framework on which to build an understanding of how DSS and related systems are built and used. It also shows how these thories and concepts are being developed in practice, and includes articles drawn from trade and academic literature, and papers commissioned specifically for this book.