Shell Method™ Software Engineering Process Repository
When the PDR first acquires a configuration item, he or she classifies it as a member of one of four classes:
Evolving items are generally stage deliverables, such as the requirements document or the design document. The key is that they were created during the development process. Evolving items often undergo revisions within a stage as well as across stages, hence the name. For this reason, as well as the fact that they are critical to the project, evolving items are among the most closely controlled items in the project.
Source items are the building blocks of the actual application. Modern development environments usually support integration with a configuration management tool to handle these numerous, rapidly changing items. Source items are difficult to handle with a manual system, due to their numbers and their frequency of update. As such, it is much more efficient to use a configuration management tool that integrates with the development environment.
Support items are things we purchase to support the design and development effort. Since they're provided by others, we do not have control over their identifiers or version numbers. We keep track of them to avoid the problem of incompatible versions of support software or hardware.
Archive items are things we want to store for posterity. These are things that are created once, rarely or never updated, and we just want to keep them around for future reference. For example, when we conduct a presentation about a specific set of requirements, we often markup that presentation based on the discussion we have. Afterward, we store that presentation in its updated form in the Archive in case we need to go back later and look at what was done.