Which road to take to BW/4HANA?
BW/4HANA is available now for more than 2 years and I got the feeling that more and more BW users are starting to think how to get there. If you do not start from scratch with BW then the process to BW/4HANA from any previous BW release is a completely new experience since it is much more application driven compared to the BW upgrades, we know from the past.
Marc Bernard provided a blog series on this topic called “The Road to SAP BW/4HANA”. This is a great starting point to get into the topic. Unfortunately, there is not the one road to BW/4HANA. Depending on your own set-up several roads are possible. Each will have specific pros and cons and the decision which road to take is a very individual one. In this blog I would like to share some ideas/thoughts which might help you to choose the right road for your scenario.
Is BW the right tool?
For someone like me working for more than 16 years with BW asking this question is strange. In my case the answer is obvious ?. However, the change from any BW to BW/4HANA is significant and therefore the effort (money and time) you must spend, will be also significant. On the other hand, staying with an “old” BW release is not future proof. I can imagine, that there are scenarios where other solutions make more sense than BW. This is now a good opportunity to evaluate your requirements and define a strategy in this area.
What can you do to prepare for BW/4?
If you answered the first question with yes, then it is time to get to know your system. Regardless what conversion approach you will follow, there are some analysis/actions which I would highly recommend doing in your existing system upfront. Just a few examples:
- Which queries/data models are used and shall be kept?
- In which state are these data models?
- Would you build them with BW/4HANA (at least) in a similar way?
- Are there any larger logical inconsistencies in your data models? For instance, wrongly modelled InfoObjects?
- What parts of your system are not used anymore and could be deleted?
- If you have been looking for the “BW hygienics” in the past, it will be a lot easier.
In combination with your current set-up (BW Release, HANA or AnyDB etc.) you should get a feeling which approaches might work.
Furthermore, you need to think how you want to work in your BW4 system in the future. It is now the perfect time to get your guidelines and naming conventions updated. Data modeling in BW4 is different compared to BW 7.0, however It can (should) be almost the same if you are already on BW 7.5 on HANA.
And finally, it is time to revisit your front-end strategy. Whether it is Analysis Office, Lumira, SAC or 3rd party software: You probably can use them already with older BW releases and start to eliminate things like BEx Web or BEx Analyzer.
When should you start with the conversion?
The answer to this question is two-fold. With the preparation you can and should start now. However, if you are anyway using a later BW release on HANA you can probably already work right now in a kind of BW/4 mode. By doing this you reduce, if not avoid, future conversion efforts.
From a feature perspective, I assume, there is no real need for the majority of customer to move towards BW/4 right away. If this applies to you, you can take your time. This gives you the flexibility to stretch the project over 1 or even 2 years.
Unfortunately, in some companies it is not possible to run projects in such a way mainly because of budgeting reasons. Also, if you are on an older BW release on AnyDB and you want to move directly to BW4, then the situation is probably different.
Will Greenfield solve all problems?
I’ve had already quite a few discussions around the different approaches and it seems that many people prefer a greenfield approach, even if their current system has almost got perfect pre-conditions for an In-place conversion. Setting up a new system is surely always an option, and, in some cases, it makes sense.
However, if I’m running a single BW landscape right now, I would prefer to stick to that. Such greenfield projects do have the tendency to last longer and I’ve seen already some cases where the old systems were running for much longer than originally expected.
I would suggest evaluating alternative approaches. For example, I could imagine doing a kind of brownfield in an existing system. To some extent being based on existing data models and some re-developments. Such an approach would also support re-naming and re-modeling where necessary. You would re-use what is already there and delete what is not needed anymore.
What can you expect from the Transfer Tools provided by SAP?
Important for the evaluation of the different approaches is to know the role of the Transfer Tools. The Toolbox is currently evolving very quickly. However, I would not count too much on them. Why?
- You create more or less 1:1 copies of the existing data models. My assumption is that every data model created on a BW before 7.4 and on AnyDB needs rework. What is the purpose of a new BW/4 system if the data models are still the same as before?
- Within the tools you have no possibility to adjust the models. Any changes must be done manually and at some point, you might be faster by copying.
- The conversion handling can also be very tedious depending on your existing system set-up. I have seen scope list of more than 50.000 objects by choosing a single object to be converted.
- The conversion process must be controlled, otherwise you will start to block yourselves.
- Now (this will surely change) it is very time consuming to keep the tools updated. Implementing/updating notes is currently daily business.
- The complete migration is very individual. There is not the one recipe which you can easily follow. You need to develop your own approach.
- Preparation is everything. Understand your current system.
- In many cases there is no need to rush.
- Do it!
Thank you, Stefan, for your point of view. You nicely list the critical questions to ask at the "beginning of the road". However, the first questions should be "is SAP BW/4HANA the right tool?" and for many long-term BW customers that means learning about sooo many new things first - especially if the existing BW system isn't running on SAP HANA. But even SAP BW on HANA customers have a big deficit because they only did technical upgrades in the past, not leveraging new features. If you find yourself in this group, the road will be longer but at the end there will be huge benefits.
The other way around, there are many customers who started with SAP BW on HANA in just the past 2 to 3 years. If you followed best practices and used on HANA-optimized objects, then your road to SAP BW/4HANA will be short. Best case you might be "just a weekend" away.
In all cases, the "first answer" is to run a SAP Readiness Check for SAP BW/4HANA, to see how much work is ahead on the road.
We understand your critique on the Transfer Tools. We ship as SAP Notes to provide flexibility and not force customers to update support packages. Still, customer who don't want to apply so many SAP Notes have the option to install a recent support package which will include most of the SAP Notes.
Similarly, we opted for a tool that can transfer a system step-by-step rather than forcing customers to go through a big-bang. There are limitations due to dependencies as you correctly noted but the approach in general works. Your request to be able to adjust objects, rename, reduce layers, etc as part of the transfer is well noted. We have several such items in our backlog and have to see when we get to those.
Thanks again for your feedback. I do like your final thought: Do it! I would add "Get started now!".
SAP HANA Competence Center
Are any tools available for migrating the bex queries and universe attached to it?
queries are not changed by the conversion tool. Your universes will continue to work as before. There are some exceptions (see SAP Note 2479683).
SAP HANA Competence Center
Thanks Marc, the EID still gets changed and I need to remap it to my universes, that's a lot of work.(Correct me if my understanding is wrong)
Considering that both the product belongs to SAP, it could have been lot smoother.
That's not correct. The technical ID of the queries stay the same. The ID will change only if you have one of the exception cases.
SAP HANA Competence Center
Great point Stefan.
Couple of point I would like to add are, I understand when SAP wants us to simplify (to improve performance) the objects and ask for conversion but my problem is with the objects where conversion doesn’t add much to the simplification/performance process and still doesn’t support direct migration/upgrade, example : Bex queries (with change in CUID, there will be huge effort on mapping the universes).
Second is about std extractor support, I think BW4HANA still doesn’t support all the earlier DS, they are updating the list regularly but I think it is not complete yet. (Correct me if I am wrong)
see above regarding queries.
In general, SAP BW/4HANA supports the same DataSources (extractors) as BW. The difference is that the protocol was changed from the Service API (S-API) to Operational Data Provisioning (ODP). Therefore your source systems must be compatible with ODP (see SAP Note 2473145) and the DataSources must be released for ODP (see SAP Note 2232584).
3.x DataSources - like all 3.x objects - must be migrated to 7.x DataSources but they continue to work as before (see SAP Note 2470352).
A different topic is moving from ERP to SAP S/4HANA. This is indeed a change where some DataSources are not available anymore (see SAP Note 2500202).
SAP HANA Competence Center
Thanks for the clarification Marc, Appreciate it.
no doubt: BW had to be changed to can survive in the future and the effort to move to BW/4 should not be underestimated.
even that I'm a friend of the In-Place Conversion, the Shell Conversion is the right approach and we don't want to talk about the other option which is still available ...
furthermore I'm a friend of a complete solution, which includes BPC and BCS in one system. that customers had to buy BPC to access one of the BW core application IP is in my opinion not really "customer friendly"
however, that was the reason why I wrote the SAP First Guidance Collection for BW on/for HANA instead of a book ...
best regards Roland