Framework for Measuring the Rationale Clarity of AEC Design Decisions

Abstract
Current architecture, engineering, and construction (AEC) design processes often rely on precedent to resolve complex decisions. However, changes to stakeholder concerns, design methods, and building products devalue much of this precedent knowledge. Project teams need to clearly communicate their decision rationale to develop consensus about design decisions. This study reviews a broad range of relevant theory from decision-based design, decision analysis, decision theory, linguistics, logic, organization theory, and social welfare. Rationale is defined as a set of assertions regarding distinct components (i.e., managers, stakeholders, designers, gatekeepers, goals, constraints, alternatives, and analysis) that support design decisions. Conditions of clarity (i.e., coherent, concrete, connected, consistent, credible, certain, and correct) are also defined. These definitions are used to measure the clarity of assertions, components, and the rationale as a whole. Taken together, this rationale clarity framework (RCF) provides a structured view that enables an objective evaluation of design decision methods.