This blog is based on a story that Nucor has presented to us. Thankfully, they have allowed us to convert their slides into this blog as we believe it is a valuable example to many other customers on how to move forward when moving their existing landscape to HANA. As you will see, they - in fact - replaced their (stand-alone) BW with a lighter version that sits within their Suite-on-HANA system (embedded BW). It is a pragmatic and real-world example of removing a separate BW instance, thereby reducing (albeit not eliminating) the need for data replication while keeping and reusing existing BW analytic models and the underlying processing by BW. So, Nucor's story goes like this:
During the initial stages of our legacy ECC to HEC ECC (SoH) migration, based on the information provided to us, we thought we could replace our legacy BW completely with native HANA modeling and analytics.
BW Replacement with HANA
On further analysis and discovery, we came to a conclusion that the custom trend analysis reporting we do based on point in time snap shots of data is not going be easy if we were to completely eliminate BW. We had three options to resolve this:
Keep BW: migrate Legacy BW to BW on HANA . This option was expensive as we had to pay for additional BW migration and hosting fees.
Eliminate BW and try to re-develop existing Dashboards, Queries, Broadcasting from Scratch using native HANA modeling and tools. This was also very expensive and very time consuming.
Embedded BW Solution: where we migrate our entire BW to the same database as our ECC HANA instance.
Embedded BW Option
So we considered Embedded BW as a potential solution. The rationale for going this direction - We were already in Nov 2015 timeframe and SoH go live was scheduled for Feb 2016. To go with one of the other options, our business was not ready to pay for additional migration / development costs and we were also running short of time to complete our BW migration in conjunction with our SoH migration. Also our legacy BW footprint was very small and usage is low. Every Monday, a user at each division will run a series of reports for submission to Corporate, and on Sunday, BEx Broadcasting will distribute dashboards via email in PDF format. We also had a brief meeting with SAP SME’s on this direction and received some great information at TechEd. We had a few challenges when we decided to go with Embedded BW route:
BI Content installation – will this affect ECC SoH?
To reduce costs we had one non-prod ECC java connected to both ECC Dev and QA ABAP stacks. Will a single BI Java support multiple backend ABAP (BW) systems without any issues?
System load and performance
Transfer of BW Objects and Data from Legacy to HEC data centers
Setting up of transfer routes and resolving transport issues
Does Embedded BW provide all BW functionalities currently in use?
Our team was able to overcome these challenges by working closely with the SAP team (HEC and Services) and successfully completed this challenging migration. We have been using Embedded BW in production for about a month now with no issues.
Embedded BW - Challenges during migration
Transports from BWP to ECD-H encountered many activation errors. Errors were resolved by activating the missing objects using BI Content and then re-import the same transports; this cycle repeats multiple times.
Transports from ECD-H to ECQ-H also encountered activation errors. Some info objects were not included so multiple attempts were necessary.
Data extraction from BWP was time consuming as it required data export from Infocube to table using Open Hub followed by data download from the table to PC file. The download to PC file has to be repeated many times since the maximum size of each file is about 150 MB. This process was used to handle about 18 GB of data.
We encountered various issues with BI Java, many of which pertain to ECD and ECQ sharing the same BI Java server.
We also encountered challenges with single-sign on for BI Java as our Active Directory user IDs do not match our SAP user IDs.
Nucor's system landscape - click to enlarge
To our Nucor colleagues for sharing this with us and allowing us to share it within this blog. This is an excellent real-world example for case 1. as described in the blog S/4HANA and #BWonHANA, maybe with a certain overlap with case 3.