Copy the report SQL to run in DB to check time it takes to complete in DB.
Schedule the same report to default Enterprise location to check the time it take to complete scheduling.
Schedule the same report to your email to check the time it take to complete (Scheduling +Email)
Create publication to deliver the same report to 1 user to check time it took in (scheduling+Publication profiling+Email)
Also can use the recommendation mention in the link:-
Tips and Tricks for SAP BusinessObject Intelligence Platform Publication