Several developers and I were recently added to a waterfall project. We were told that the project was almost done but needed a few extra coders to help finish it up (that's the first mistake). We were all assigned different modules to work on.
This phase of the project became more agile in that we were doing nightly builds and deployments to a test environment and the qa team was actively testing and reporting bugs. Occasionally our regression tests on the new modules would fail - stuff that used to work no longer worked. We discovered that there were design changes being made that only involved the developer working on the module and the architect and PM. The problem was that this affected the modules of other developers.
The developers got frustrated with one another, asking that they be informed of design changes, because it may have an impact on their work.
What is the best way to communicate design decisions that may be made in a hallway conversation or an email between a few parties. Should there be a formal process for handling design changes, even if they are extremely minor?