Just an example, I had the non-deterministic case using JAXB to generate java classes from XSD Schema files. Running an ANT jaxb task to generate the classes from the same schema files would generate different class files each time. The class files were functionally the same, however it would reorder methods, the order of the variable definitions etc. Possibly due to some internal code using a Map vs List, so order was not guaranteed. In our case the schema files were in Source Control, the Java/Class files were not, the Java/Class files were generated by the build, packaged to a jar and published to our artifact repository.