what is the PQL formula to find the rework time?for eg : we have the activity name as the dimension and i want the first occurrance of that activity to last occurrance of that activity (rework time) as the kpi in the OLAP tableplease help

I can't give you an answer. My guess is that you need something like

AVG(CALC_THROUGHPUT ( FIRST_OCCURRENCE["AT_ACTIVITY"."_ACTIVITY_NAME"] TO LAST_OCCURRENCE["AT_ACTIVITY"."_ACTIVITY_NAME"],REMAP_TIMESTAMPS ("AT_ACTIVITY"."_TIMESTAMP", DAYS )))

but it doesn't work in the OLAP.

HTH