Although a substantial amount of literature advocates the integrated collaborative design processes for construction projects, very little explicit knowledge exists about the impact of the integrated processes on project uncertainty. In contrast with construction site processes, which can in most cases be organized as a sequence of tasks mutually interlinked by technological interconnections, design is a highly interdependent and iterative process that needs different management approaches. To manage the complex interdependencies of design, managers need to make sense of how far-reaching the impact of addressing a particular requirement will be on project outcomes. By using the theoretical dichotomy of wicked and tame problems, this paper conducts a study on a design and engineering mega-project to induce the shortcomings of traditional project management applied to complex design problems. This study develops a cognitive map of how a requirement propagates through the entire scope of an ill-structured design problem and contends that the traditional design management techniques do not capture the ill-structure of the design sufficiently. The paper finally develops a list of theoretical propositions and an accompanying set of practical recommendations that are based on the notion that design should be managed on the basis of distinguishing between wicked and tame parts of the problem. The study contributes to design management literature with an early normative framework for managing complex construction design.