Trading Project Costs and Benefits in Multi-Attribute Tradespace Exploration

Classical Cost-Benefit Analysis (CBA) is a preferred method for the evaluation of large-scale infrastructure investment projects in the private and government sector. This paper proposes the use of a method for tradespace exploration as an iterative to classical CBA to help overcome some of its shortcomings. Multi-Attribute Tradespace Exploration (MATE), a method for system decision making and design, allows the tradeoff of both desirable and undesirable system (and project) attributes. Undesirable attributes impose “costs” on stakeholders, which can be traded off in a similar manner to desirable attributes, which supply “benefits.” This method possesses several advantages for the treatment of monetary and non-monetary attribute types compared to classical CBA. Utility for different stakeholders is kept separate, avoiding controversial interpersonal utility aggregation and comparison. Tradeoffs among different types of non-monetary attributes are made explicit. Large numbers of designs can be assessed rapidly, allowing for the exploration of patterns in the tradespaces that may help facilitate negotiations between stakeholders. In order to illustrate the proposed approach, this paper compares the evaluation of a project using classical CBA and MATE through application to an example case from the transportation domain, an airport express from downtown Chicago to O’Hare International Airport.