Parallel development takes place for two key reasons:
· Scheduling of work within a single release across two or more developers. Different developers may require concurrent update access to the same programs. This type of parallel development is not covered by this document as this is viewed as a project management issue and should be avoided where possible.
· Concurrent updates to support two or more releases of the application. These updates may be performed by the same person or by different persons. Examples of parallel development are given below.
This type of parallel development takes place when a live system is undergoing future development work whilst at the same time undergoing change for live maintenance support. This is very common and can only be eliminated if the release cycles for development and support releases are synchronised.
This type of parallel development takes place when a system is undergoing two threads of development work each aimed at a different release.