Data loading Delayed in P System

Hi,

Today i've encountered a problem with huge volume of data. Actually one load 'll complete with in an half an hour, but today it takes almost 5 hrs. this load got delay due to huge volumeof data.. Finally the load 'll completed.

My problem is how can we analyse whether the records are fetching from BW side or at source system side.

If the problem with source system only, i mean that if it fetches huge volume of data how can we analyse this one?

Plese any one help me out?