# Parallel Development ## PM2-Agile Guide Glossary Parallel development occurs whenever a software development project requires separate development efforts on related code bases. For example, when a software product is shipped to customers, a product development team may begin working on a new major feature release of the product, while a product maintenance team may work on defect correction and customer patch releases of the shipped product. Both teams begin working from the same code base but the code will necessarily diverge. The code bases used in parallel development efforts must be merged frequently to ensure, for example, that the defect corrections provided by the product maintenance team are integrated into the major release the product development team is working on.