In the course of their decision activities managers work with many pieces of knowledge. Some of this knowledge is descriptive, characterizing the state of past, present, future, or hypothetical worlds. Such knowledge is commonly called information or data. Other pieces of knowledge are procedural in nature, specifying how to accomplish various tasks. In addition to "know what" (information) and "know how" (procedures), a manager may work with reasoning knowledge on the way toward reaching a decision. This third kind of knowledge indicates that certain conclusions are valid under particular circumstances. Two other kinds of knowledge are very much concerned with communication. One is linguistic knowledge which enables a manager to understand incoming messages. Conversely, a manager works with presentation knowledge when constructing outgoing messages.

Managers are first and foremost knowledge workers who are involved in the making of decisions. Sometimes, a manager makes decisions individually. In other cases, decision-making may be distributed, involving the combined and coordinated efforts of many knowledge workers. Both individual and distributed decision making are susceptible to support by systems that facilitate, expand, or enhance a manager's ability to work with one or more kinds of knowledge. Such knowledge-based systems are called decision support systems (DSSs).

This book focuses on computerized decision support systems, emphasizing a knowledge-management perspective. With the relentless advances in the technology and economics of computers, we are rapidly reaching the point where a manager's success depends on his or her understanding of DSS possibilities and skill in DSS application. This book is designed to foster a comprehensive understanding of DSS possibilities and, used with workbook supplements of an instructor's choosing, impart practical DSS development and usage skills.

Many DSSs are oriented toward individual decision support. There is growing interest in DSSs that directly support distributed decision making at the group, organization, and inter-organization levels. Both individual and multiparticipant DSS orientations are examined in this book.

Decision support systems also differ with respect to the kinds of knowledge they help manage. The majority of conventional DSSs have been devised to help manage primarily descriptive and procedural knowledge. In contrast, there is a class of artificially intelligent DSSs concerned mainly with the representation and processing of reasoning knowledge. Both conventional and artificially intelligent DSSs are examined in this book. Indeed, we explore computer-assisted management of every major type of knowledge relevant to supporting decision activities.