Should I add a non-requested work to my major revision of a scientific journal paper? I am wondering if I should follow the advice of my co-advisor or a relative of mine who is also a researcher and used to write a scientific paper in the same field (but currently with less experience then my co-advisor).

I will make it a bit more clear:


I am a Ph.D. student in CS, specifically in networking, I wrote a scientific paper that I have sent to an Elsevier journal.
Last month, the journal replied to my submitted paper and requested a major revision; so I know that I have a bunch of rework to do.
One of three reviewers was complaining about the contribution and evaluations/simulations that I have done, while the other two didn’t complain in the same manner.
Following to this and in order to make it clearer for the complaining reviewer, my co-advisor advised me to add a small simulation/evaluation to my paper to clarify the contribution and justify why we considered various scenarios in terms of scale.
In the meanwhile, I asked a relative for help, he said that it is not a good approach to add this simulation/evaluation since no reviewer asked for it, and could be harmful to my work/my chances to being published.


While I can agree with my relative about adding a non-requested work, my intuition pushes me to follow my co-advisor, since this is a little work that can clarify, justify more the need for considering various scenarios (which I have done and the reviewer didn’t understand why I did it).
As somebody in a different area of computer science, I find it hard to see how including a little more true, relevant information could possibly be harmful. The reviewers think your paper is worth publishing with revisions. The worst case I can see is that, when you submit the revised version with this extra unsolicited material, the referees ask you to remove it again.

You can always mention your parent's opinion to your co-authors and see what they think.