The field variously described as multicriteria decision making (MCDM) or multicriteria decision analysis or aid (MCDA) is that branch of operational research/management science (OR/MS) that deals with the explicit modelling of multiple conflicting goals or objectives in management decision making. Standard texts in OR/MS typically do include identification of objectives (often stated as plural) as a key step in the decision-making process, but the ensuing discussion appears to assume that such objectives are easily aggregated into a single measure of achievement which can formally be optimized. The field of MCDA, however, arose from a recognition that systematic and coherent treatment of multiple objectives requires structured decision support to ensure that all interests are kept in mind and that an informed balance is achieved. See, for example, the discussions and associated references in Chapter 2 of Belton and Stewart: Multiple Criteria Decision Analysis: An Integrated Approach. Kluwer Academic Publishers, Boston (2002) and Chapter 1 of Figueira et al. (Eds.): Multiple Criteria Decision Analysis—State of the Art Annotated Surveys. International Series in Operations Research and Management Science, vol. 76. Springer, New York (2005).