is this what refactoring means
is this what refactoring means
Changes in how ATCs operate
Changes in how pilots operate
Changes in how airplanes receive these instructions (including the flight software itself, safety systems, etc.)
Changes in how airplanes are tested
Changes in how pilots are trained
Etc. In this case, the refactoring requires changes to hardware, software, training, manufacturing, and humans.
Functionally, I suppose it's the equivalent of upgrading an ID field that was originally declared as an unsigned 32 bit integer to a wider 64 bit representation. We may not be changing anything fundametal in the functionality, but every boundary interface, protocol, and storage mechanism must now suffer through a potentially painful modification.