Engineering designer B designs a height-adjustable equalising device for a particle- board production plant. While designing a lifting-frame he asks his colleague F from the planning department for the dimensions of the frame-structure of the plant, which is a prior spatial requirement for the component that he is working on. The planner F cannot help him at once, but he promises to look into the existing layout drawing of the framework and to inform B later on. In order to continue his work B tries to derive an average measurement of the dimensions by analysing the neighbouring components, but this attempt is not successful. Thus, B insists on definitive information three days later. Now F tells him that he can design a support for his 1 Frankenberger, E and Badke-Schaub, P Integration of group, individual and external influences in the design process. In Frankenberger, E, Badke- Schaub, P and Birkhofer, H (eds) Designers—the key to suc- cessful product development Springer, London (1998) www.elsevier.com/locate/destud 0142-694X/99 $ - see front matter Design Studies 20 (1999) 465–480 465 PII: S0142-694X(99)00017-4  1999 Elsevier Science Ltd All rights reserved Printed in Great Britain Analysis of design projects Petra Badke-Schaub, University of Bamberg, Department of Psychology II, Markusplatz 3, D-96045 Bamberg, Germany Eckart Frankenberger, University of Technology Darmstadt, Machine Elements and Engineering Design, Magdalenenstraße 4, D-64289 Darmstadt, Germany (Now at: SME-PI, Heidelberger Druckmaschinen Aktiengesellschaft, Kurfursten-Anlage 52–60, D-69115 Heidelberg, Germany) The contradicting conditions of modern product development are well- known and often claimed: engineers have to collaborate in differently organised projects under time constraints, and they have to meet high quality requirements at the lowest possible price. But how can they be supported? Attempting to answer this question we need to know, what factors influence teamwork in engineering design practice, when (in what situation) they are of importance in the course of a project and, of course, how they interact. This paper presents an approach designed to answer these questions by empirical investigations in industry and highlights selected results on mechanisms that lead to success or failure in product development.  1999 Elsevier Science Ltd. All rights reserved Keywords: case studies, design research, psychology of design, teamwork, decision making This paper is based on Frankenberger and Badke-Schaub 1 and was updated and revised for this Special Issue.