This is the first dedicated book to be published on computer-aided General Morphological Analysis (GMA) as a non-quantified modelling method. It presents the history and theory of GMA and describes how it is used to develop interactive, non-quantified inference models. Eleven case studies are presented out of more than 100 projects carried out since 1995, illustrating how GMA has been employed for structuring complex policy and planning issues, developing scenario and strategy laboratories, and analysing organisational and stakeholder structures. Also discussed are the concepts of "wicked problems" and "social messes", their characteristics and treatment, and problems concerning the facilitation of morphological analysis workshops.