Many projects are trying to use common code. There is a shared repository that all the projects access. This pattern applies if there is a Strong Code Owner [pattern to be written] or if there is weak code ownership, or no Benevolent Sponsor [pattern to be written]. Someone (or some project) wrote the code in the first place and contributed it to the repository. The common code is a small percentage of the overall deliverable from any of the projects. Each project has its own delivery schedule, set of deliverables and customers.