Drivers of complexity in new product development projects : why are some projects more complex than others?

Project complexity has recently become an important element of project management theory and, therefore, has attracted a lot of attention from academics and practitioners alike. However, what does project complexity mean and what are its contributing factors is still unclear and confusing. The aim of this paper is to structure the different factors described in the literature so far and articulate them into a new framework of project complexity. This new framework integrates both the structural complexity dimension and the uncertainty dimension of project complexity. These general dimensions are then applied to the specific case of NPD projects to generate a new framework for this important class of projects.