In the first volume of the set, Evaluation and Decision Models: A Critical Perspective, the purpose is to provide a critical thinking framework for all individuals utilizing decision and evaluation models, whether it be for research or applications. In the book, the authors criticized formal models while pointing out where these models can be useful. On the other hand, Evaluation and Decision Models with Multiple Criteria is a guide, a way of reasoning aimed at helping the analyst to choose a model and use it consistently. The authors propose, often using an axiomatic point of view, a sound analysis of techniques aimed at supporting the decision aiding process. The presentation is carried out within a unique framework that can be extended to most decision and evaluation models, as a decision aiding methodology .