Software quality is tightly controlled using issue tracking, automatic testing or merge requests, and collaborative code review.
Bison through MOOSE is supported by more than 2000 tests. All new code must be supported by testing.
Bison includes verification tests for linear elasticity, large strain behavior, heat transfer, contact, and many other capabilities. Details can be found in "Verification of the BISON fuel performance code".
Bison capabilities have been most thoroughly validated for light water reactor fuel performance modeling. Details can be found in "Validating the BISON fuel performance code to integral LWR experiments" and "Assessment of BISON: A Nuclear Fuel Performance Code".