We have got an old system Qwerty1
- that makes a lots of things,
We also have another system Querty2
it's actually a remake of Qwerty1
(for several reasons)
Notice we still are live with Qwerty1
.
Now we want to be sure for all tested input data in Qwerty2
we get the same output data
in both systems.
What is this methodology called?