Deciding a Sustainable Alternative by ‘choosing by Advantages’ in the Aec Industry

When deciding what alternative is more sustainable than others (i.e., selecting materials while considering environmental-, social-, and economic outputs) in the AEC industry, stakeholders need to select a method for their decision-making process. From the literature it appears to be assumed that all multiple criteria decision analysis (MCDA) methods are equal or that the differences between them does not matter, and it is left to the user to select any one. In this study we argue that methods matter. This paper explores what characteristics make a method viable and, correspondingly, what characteristics disqualify methods. We compare and contrast value-based methods versus Choosing By Advantages (CBA). In addition, we explore what characteristics would make a method be aligned with lean thinking. We have found that methods that rank factors or values, such as value-based methods, require a high level abstraction, inducing unanchored conflicting questions. In contrast, CBA methods base judgments on anchoring questions, which are based on valuing the importance of advantages between alternatives. CBA produces fewer conflicting questions and allows stakeholders to discuss what they value in a richer context. We discuss why we think that CBA methods are superior to other methods for making sustainability decisions. In addition, we discuss why CBA is in line with lean thinking.