Engineering processes can be broken down into process modules that are connected by interfaces. All processes conform to the metamodel, so the process modules also conform to the metamodel. Certain projects contain the same parts of a different process, which is the process module. Stages allows a process module to be used in multiple different project- or program-specific processes so that you only need to make the process one time rather than creating it for every project. By breaking down processes into process modules, changes can be made quicker and with less risk for the overall system, and review and approval cycles can be reduced allowing for an earlier practical use.

Ex. A car manufacturer has three different versions of a model. The differences in the models are the engines. The same process of making the body of the car is in all of the models. The entire process for the car was created and then the modules that are the same in each model are used for each.

Probably need a better example ^^^^^

TBD