Requirements analysis is a complex task. All too often, information systems that do not fulfil users' requirements are built and delivered, In software engineering, viewpoint analysis has been proposed as a means of successfully capturing user requirements for complex systems. Viewpoint analysis is a process that produces a synthesis of requirements from a number of disparate and distinct perspectives. This paper describes such a viewpoint analysis that has been applied to the field of Concurrent Engineering. A viewpoint reference model is proposed which draws on the experiences of a number of existing models from fields such as manufacturing, information systems and distributed computing. This new reference model, the CE-RM, has been designed using object-oriented methods and has been used as a basis for building a Concurrent Engineering support environment. A description of the implementation of this new support environment is given, outlining its supporting computer systems architecture and information system model. The CE-RM is discussed and compared with a number of existing models that have been proposed to capture requirements in the manufacturing and engineering domains in order to validate the viewpoint analysis approach. (C) 2000 Elsevier Science B.V. All rights reserved.