Software Configuration with Information Systems

There is no aspect of software engineering tha t does not require versions. Software is versioned, individual components are versioned, so is documentation. Although the presence of versions at all levels complicates the builds of large systems, these must be handled correctly, because software will evolve. Software configuration designates the building of a system from its components. This process might be single-layered, in which a complete system is built directly from atomic components, such as source, text or graphics files; or multilayered, in which case subsystems are successively built up from component subsystems, which have themselves already been configured. At each level, each system or component -hereaf te r called a module--can have several versions. We call the set of conceptual (possible) versions--those tha t can be imagined or "thought o f " o f tha t module its conceptual version space, and the set of physical versions of that module its physical version space. Key to successful, au tomated software configuration management is the structure of these version spaces. In particular, we need a model fo r constructing version spaces where the following issues are considered to be fundamental.