This dissertation presents the results of a Ph.D. project entitled: management and engineering of virtual enterprises. The research addresses preparation and set up of virtual enterprises and enterprise networks. A virtual enterprise (VE) can be perceived as a customer solution delivery system created by a temporary and re-configurable information and communications technology (ICT) enabled aggregation of competencies. The project has been closely affiliated and funded by the international research project GLOBEMEN (Global Engineering and Manufacturing in Enterprise Networks, IMS-project 99004, the European part of the project was funded by the EUs 5. framework programme, IST-1999-6002). GLOBEMEN had 19 partners from Australia, Japan and Europe, of which 11 were from industry. In total the workload exceeded 1000 person months. The main achievements of the project includes: * A) Clarification and definition of the concept for virtual enterprises and enterprise networks including preparation of these. - A fast and efficient setup of virtual enterprises can be enabled through the establishment of an enterprise network in which an appropriate type and degree of work preparation can be established prior to the set up of virtual enterprises. Types of work preparation include definitions (e.g. shared terminology), ICT support (e.g. infrastructure and applications), procedures (e.g. how to set up virtual enterprises, partner selection), reference models (e.g. contract models and product structure) and the like. * B) A framework and a reference architecture for virtual enterprises named VERAM (Virtual Enterprise Reference Architecture and Methodology) and VERA (Virtual Enterprise Reference Architecture) respectively. - VERAM is a framework that structures the body of knowledge related to preparation, set up and operation of virtual enterprises and enterprise networks. VERAM is based upon GERAM (Generalised Enterprise Reference Architecture and Methodology), which is a part of the international standard ISO 15704:2000. - VERAM consists of 3 layers: 1) Basic layer: describes the Virtual Enterprise concept, the view on GERAM applied in VERAM 2) Structuring layer: consist of the VE Reference Architecture (VERA) based upon the GERA modelling framework of GERAM. VERA captures the VE concept of the basic layer and consists of three recursive entities: enterprise network, virtual enterprise and product life cycle entity. 3) Component layer: consists of reusable components and modules. - Each layer builds on the previous one, i.e. the VE concept is captured in VERA, and the VERA can be used to structure each of the VERAM components. * C) A methodology for virtual enterprise named VEM (Virtual Enterprise Methodology) - One of the central parts of VERAM. Applying VERA as its basis structure the VEM consists of a set of guidelines, which systematically describes activities that enterprises should consider in relation to set up and preparation of own enterprise networks with the aim to set up virtual enterprises.