The purpose of this chapter is twofold: i) to focus attention descriptively on some important aspects of decision making in teams - namely; the sense making process, the nature of multiple perspectives and interpretations, the interdependency of problems that make up a difficult and messy situation, the nature of purposeful behaviour - goals systems, and perspectives on psychological and social negotiation; and ii) to explore ways of translating these descriptions into prescriptions that might reduce the probability of decision failures. The description of decision making and problem solving processes presented in the chapter links directly with some of the aspects of decision making that might decrease the probability of failures. Theories from psychology, social psychology, group processes, the nature of problems and psychological and social negotiation are used as a basis for description. The chapter introduces cognitive and causal mapping as a method for describing and managing decision situations including: sense making, multiple perspectives, and goals systems. The chapter also considers the use of causal mapping as a tool for facilitating negotiation in teams and so aiding the reaching of agreements about how to act. In addition the chapter discusses the role of group support systems (GSS) and operational research in addressing aspects of decision failure. In particular the use of a GSS is argued to address delivering a balance between the potential benefits and potential dangers accrued from drawing multiple stakeholders into decision making situations. The chapter draws particularly upon the research of Nutt that led to his analysis of failed decisions (Nutt, 2002)