A layered approach to very large system specification

Many information system endeavors fail (in terms of cost overruns, late delivery, or absolute inability to meet real needs). This is primarily still a matter of lack of effective communication by the various participants. Some possible improvements are discussed. They include: (1) adoption of engineering practice over all concepts, such as performance and safety, in the early stages of the definition; (2) use of a layered approach, where the design progresses in a top-down fashion, with few constraints at the start and assertion of more constraints until the definition is formal at completion; (3) better interaction and diagnostics among the various definition parts