I have a report broken down by a group called "range group" and then within this by a take on period. The report shows new business by take on period for each group, payments after month 1, month 2, etc for each take on period and the payments as a percentage of the new business. Part of each batch of new business may be written off at certain points in time. I therefore need to know the payments as a percentage of the new business less write offs. I have created a running sum field to calculate new business for each take on period. However, it seems to calculate it for each take on period all the way through every group. For example, if range group A had new business of £50 in March 06 and range group B had new business of £25 in March 06 I would want to see the running sum for range group B to be £25 but the report is showing £75. My formula currently says "=RunningSum(<Net Instructed Val(£)>;<Take on Period>)". I want it to calculate based on the take on period AND range group. Is it possible to have a running sum on 2 variables in Desktop Intelligence?