S_ALR_87013611 Statistical Posting field Stat. Plan

Hi All,

i run report S_ALR_87013611 and the report is having two parts, True Posting and Statistical Posting. My transaction is using WBS as statistical posting.

In statistical posting it has field Stat. Plan. Could anyone tell me, from which transaction will the figure in field Stat. Plan taking? as currently the field is blank. My assumption is it will come from WBS element budget load, but it doesn't appear even though i load the budget.