BO migration from BEx reports

Question

One of my client is running on SAP IS Retail 6.0, and they have few BW reports. Now they are looking for migrating the BEx reports to BO XI.
They do not want to change anything, but want to port the reports as is to BO from BEx.
My previous experience of porting BEx reports to BO as is, without puting extra filters of something, to reduce the huge data size images was not good at all.
Is there any way to have better performance in BO than the current BEx performance, if we want to port the reports as is without any structural change?
Please share your experience with me.

Answer 1

My company is running Webi reports using BOBJ XI 3.1 (up to current fixpack level) on SAP BI 7.01 EHP1-SP5. This config gives 50% reduction in Memory, 30% improvement in runtimes, on average compared to 7.0 BI, according to SAP. But is it good enough for full corporate deployment?
My understanding of the Webi <-> SAP BI architecture is that we still have a large image sent to the XI Box from the query -> universe -> Webi report refresh. The big flaw here in my view is that Webi is disconnected from the OLAP database tables after the refresh, thus must 'image' everything the report requires, in our case into a 32 bit Windows NT box. 
This is quite different from the SAP BI OLAP front-end model, in which user navigations are threaded in various ways (sometimes from cache, from aggregates, from indexes on the DSO characteristics etc), as we can see in our BI OLAP processing steps in BI statistics.
After the Webi refresh, there are no 'threads', or calls, back to BI ABAP tables, as the Webi report has to represent all the potential navigation in the MDX model. For this reason it seems a fundamentally resource-intensive architecture, that can induce instability when very large sets of data are retrieved in concurrent user sessions. By "large"  think of the 'cubed' size (count of characteristics X count of key figures X number of transactions).
If user activity results in concurrent refresh calls to generate large report 'images' from SAP BI, I have observed 100% CPU freeze in BOBJ XI, and user lockout until resources are again freed up, which can take a very long time for certain reports. Subsequently when the large images are subjected to user OLAP navigations, CPU processing again will spike.
When running large image reports, the Webi performance has been an 'order of magnitude' slower than our reports running on ABAP web. Unfortunately, the risk is greater than just slow performance - there is the CPU and memory resources that are engaged during that extended processing interval as well.
Much depends on the normal level of user activity. This is a matter of simple statistics. Say your overalll production BI system load averages ten users per hour running reports. If Webi report runtime averages 30 minutes per refresh, and BEx ABAP runs in 5 minutes, the probabillity of concurrent resource collisions is much higher - from 10% to 50%, thus the situation can snowball rapidly.
I think SAP is working very hard on this problem, but has issued guidance as recently as May 2009,  that if you have current BEx reports that are working, don't migrate them all yet. Unfortunately our users are anxious to run everything in the Webi tool, because it is indeed a super user interface.
However, customers have until 2016 until the Bex tools are phased out. Interviewed by Searchsap, Jonathan Becher, SAP Sr. VP, said, "There are lots of scenarios that BEx does just fine, if you're confident using BEx, don't rush."  The same article also quoted Cindy Coyle of Coors, who had tested the Webi BOBJ: ""Don't go near Business Objects [until you get a BWA]," Coyle said, "because it'll only add more performance problems on top of what's there today." Article: http://bit.ly/2HJUqf
Edited by: Douglas Grant on Oct 18, 2009 7:26 PM
Edited by: Douglas Grant on Oct 19, 2009 9:51 AM