Design through documentation: the path to software quality

In traditional engineering design, preparation of a sequence of documents precedes the actual construction begins. Each document is used for review and analysis and, after revision, serves as input to the next phase in the development. When errors are discovered or changes are required, the design documents previously approved are updated and reviewed again. Each new document is reviewed against the previous documents. Whenever a document is revised, those based on it are reviewed and revised if necessary. In software design this approach is rarely properly applied. Practitioners seem unable or willing to write the precise documents that would be required. Instead, they write vague statements that cannot be subject to rigorous analysis and are of little value to those making the next decisions. We will provide precise definitions of a set of software documents and how these documents can be produced as part of an improved software development process.