During the initial development, for example, for a proof of concept, it is common to have one developer working on the system with a full release of an RPD from development to production. At that moment, change control is simple as the whole updated RPD is kept with versioning via a third-party tool, such as Visual SourceSafe (VSS) or Subversion (SVN).
However, as a project matures in a live environment, you may have minor changes that are made online or quick point releases made directly to production in order to support urgent user requests. In parallel, we would commonly be developing a major DEV to PROD release as a part of the next stage for the project.
This means that you need to merge changes from both the amended PROD RPD and the ...