convergence plot normalized value meaning

hello,

from what i understand, when the plot is horizontal for displacement, this means the results have converged. 

im not too sure how normalized value is calculated, is the formula available somewhere so i can understand what it means?

As i do more and more loops, target acuracy gets lower, im assumming, this means it is getting more and more acurate, right?

thanks

SolidworksSimulation