What type of analysis can be done for case study grid independence?
 

I am working on Backward Facing Step analysis. First I need to justify grid independence. I need several methods to justify it. One of it is using velocity measurement at length 200 micron using a line.

Is there any more type of analysis that I can do?

Use whatever measures are important for your analysis. Separation length and pressure loss are two other parameters you may wish to consider.