This chapter indicates the general characteristics of Problem Structuring Methods (PSMs), and of the situations in which their use should be considered. It provides brief description for some principles. Different PSMs have their own particular ways of providing structure to the discussion of 'wicked' problems. Each has its own particular sequence or array of processes with associated tools or techniques. It may be helpful to indicate their range by providing brief summary descriptions of some of the more widely used PSMs. The chapter discusses the significance of this development in the context of planning, evaluation, and more generally. Strategic Choice Approach (SCA) is a planning approach centred on managing uncertainty in strategic situations. Facilitators assist participants to model the interconnectedness of decision areas. A problem focus of a small number of decision areas is agreed, pro tern, based on their interconnectedness, urgency and importance.