4.7. SOFTWARE VALIDATION AFTER A CHANGE
Due to the complexity of software, a seemingly small local change may have a significant global system
impact. When any change (even a small change) is made to the software, the validation status of the
software needs to be re-established. Whenever software is changed, a validation analysis should
be conducted not just for validation of the individual change, but also to determine the extent
and impact of that change on the entire software system. Based on this analysis, the software
developer should then conduct an appropriate level of software regression testing to show that
unchanged but vulnerable portions of the system have not been adversely affected. Design controls and
appropriate regression testing provide the confidence that the software is validated after a software
change.