Regression

When a feature stops functioning as intended after some kind of of change to the system is integrated, it is called regression. Originally the term regression referred to a change that caused a previously fixed bug to reappear, but the term has evolved to describe any kind of change that breaks existing functionality. There are many kinds of regression that may occur in practice.

-ns-3 testing documentation

Why use simulation?

The main reasons to use simulation are:

1. Diagnosing process issue

2. Test performance improvement idea

3. Evaluating decisions

4. Stress test a system