rating surface roughness using solidworks - question

hello all!
 I have severel surfaces as solidworks parts, I want to find/form a method to rate them according to thier roughness and use some methamtical/physical equations to base it on, 
 !I'll be happy for any help or suggestions  

 I've added two Part files for examples here-
surfaces.zip - Google Drive 

SolidworksSurfacing