This post explains how to add an element in your model that gives the rank of a result...

This uses the analytic function rank() OVER of SQLServer or Oracle:
rank() over(order by sum(amount) desc)

as example, we consider that we have a model build like this: the Order Date as a Row element, and the Sum of Amount as Data element...
the basic result table in you report looks like:
date amount
1/1/2000 120
1/2/2000 180
1/3/2000 110

to add a rank() column:

• drag and drop again the Amount element in your Data elements
  
• rename it to Rank
  
• expand Advanced and set the Custom SQL property: rank() over(order by sum(amount) desc)
  

this will add the rank column and your result table will look like this:
date amount rank
1/1/2000 120 2
1/2/2000 180 1
1/3/2000 110 3

rank() is an example but you could use other aggregate/analytic functions provided by the database engine...

Edited by user Tuesday, May 13, 2014 2:27:29 PM(UTC)  | Reason: Not specified