Originally Posted by
Ian W
This is true, But that doesn't excuse avoiding regression testing. The new use might just have some operational assumptions such as parameters that the designer of the legacy system believed 'would never be exceeded' - and all the people who knew of those parameters and the operational assumptions that drove them are long retired.
Yes. That's a perfect example of a circumstance in which software (or hardware) that may have been more than adequate for long periods of time and in various use cases must be reexamined and retested when a new use case arises. Or else.