to manufactured products and CAD. An example can be taken from Boeing's experience. The 777 Program took on the challenge of having a digitally-defined plane. That required an investment in large-scale systems, databases, and workstations for design and analytical engineering work. Given the magnitude of the computing work that was required, KBE got its toe in the door, so to speak, through a "pay as you go plan." Essentially, this technique was to show benefits and then to obtain more work (think agile engineering) thereby. In the case of the 777, the project got to where influences to changes in the early part of the design/build stream (loads) could be recomputed over a weekend to allow evaluation by downstream processes. As required, engineers were in the loop to finish and sign off on work. At the same time, CAx allowed tighter tolerances to be met. With the 777, KBE was so successful that subsequent programs applied it in more areas. Over time, KBE facilities were integrated into the CAx platform and are a normal part of the operation. KBE and knowledge management One of the most important knowledge-based technologies for KBE is knowledge management. Knowledge management tools support a wide spectrum repository, i.e., a repository that can support all different types of work artifacts: informal drawings and notes, large database tables, multimedia and hypertext objects, etc. Knowledge management provides the various group support tools to help diverse stake holders collaborate on the design and implementation of products. It also provides tools to automate the design process (e.g., rules) and to facilitate re-use. KBE methodology The development of KBE applications concerns the requirements to identify, capture, structure, formalize, and finally implement knowledge. Many different so-called KBE platforms support only the implementation step, which is not always the main bottleneck in the KBE development process. In order to limit the risk associated with the development and maintenance of KBE application, there is a need to rely on an appropriate methodology for managing the knowledge and maintaining it up to date. As example of such KBE methodology, the EU project MOKA, "Methodology and tools Oriented to Knowledge based Applications," proposes solutions which focus on the structuring and formalization steps as well as links to the implementation. An alternative to MOKA is to use general knowledge engineering methods that have been developed for expert systems across all industries or to use general software development