This book presents applications of the Analytic Hierarchy Process developed by Thomas L. Saaty to deal with unstructured decision problems, together with case histories developed by him and in collaboration with others in areas of current societal concern. Its purpose is to provide the reader with examples of how to deal with unstructured problems, particularly ones involving socio economic and political issues with qualitative and intangible factors. These examples show how to use judgment and experience to analyze a com plex decision problem by combining its qualitative and quantitative aspects in a single framework and generating a set of priorities for alternative courses of action. The process has inherent flexibilities in structuring a problem and in taking diverse judgments from people, whether singly, in a group working together, or by questionnaire. Decisionmakers will profit from this approach. It makes accessible to them a framework for understanding the complexity of the system they are in as it impinges on the surrounding environment. To deal with complexity, we must first understand it. Systems thinking is necessary if all the important factors are to be considered. Complex systems problems can challenge and tax our logical capability to fully understand their causes and the consequences of any action we may take to solve them. Neverthe less, in time their effects on us tend to become better known than their causes.