Sir can you say in which lecture you have talked about sensitivity analysis. I wanted to do revision but I forgot where was it.Was it Decision tree video?
I do not discuss sensitivity analysis in my lectures because it is vary rarely asked in Paper PM (it is much more relevant for Paper FM and is included in the Paper FM lectures).
If you are asked to calculate the sensitivity of something, then it is the % change in that item that would result in a change of the decision.