Hi,
the planning buffer is filled with data only when opening the bex workbook.
So any changes to the attributes, while the workbook is open, will not be read into your planning buffer.
After changing the attributes, you need to have a full server roundtrip - meaning you need really to reload all data into your planning buffer.
It´s not really easy.
for BI IP it was never implemented to have attribute planning...
regards
Cornelia