Today we have no generally agreed upon architecture of virtual enterprises. In this paper, a general architecture for virtual enterprises is proposed, based on GERAM (ISO/DIS 15704). First, the extended and the virtual enterprise are compared, and the most essential of the concepts used in GERAM are introduced, followed by a presentation of the virtual enterprise architecture. Subsequently, by examples, the broad denotation of the virtual enterprise concept is illustrated by the architecture, after which the focus is limited to so-called focused networks of companies exploiting the potentials of the virtual enterprise. For focused networks the virtual enterprise architecture is explained in depth by an example. The next chapter discusses VE concepts, typology and methodology for these virtual enterprise focused networks. As regards concept classes of use, an example of so-called situational factors and design parameters is presented. In addition, a typology or reference architecture for knowledge production is described, followed by a discussion of the basic issues of a methodology.