If you're one of the 17,000+ SAP BW customers, you are likely to have seen that SAP has launched its 2nd generation Data Warehouse, SAP BW/4HANA. You are probably wondering what approach you should take to get onto it.
The good news is that there is a straightforward approach to this and there are two options. It's possible to either migrate and upgrade your existing BW system onto BW/4HANA, or alternatively to start with a fresh install and migrate your objects and data. Let's get into some detail.
Migrating and upgrading your existing BW system
This is the most obvious solution for existing customers but take the time to do the analysis and make an informed decision before you jump into this. In almost every case, customers who started with BW on HANA will prefer this option. It is a simple three step process:
Step 1 - Upgrade to SAP BW 7.5 SP04 on HANA
SAP BW 7.5 SP04 is the release where the magic happens and it needs to be your target. If you've got an in-flight project and you don't want to consider SAP BW/4HANA at this time, you need to make sure you're upgrading to BW 7.5 SP04 or higher.
SAP's DMO tool allows you to get from just about any database and any version of BW to SAP BW 7.5 SP04 in a single step, so there's really no reason to go to any other version right now.
Make sure that you do some housekeeping as part of this - many older BW systems have very big database tables full of old housekeeping data. Keeping these is just a cost, on SAP HANA.
Step 2 - Commence the object migration
The great thing about getting onto BW 7.4 SP05 is you can commence the object migration. This can be complete in a Big Bang approach, or alternatively it can be done over a period of time, according to business priorities.
Report RS_B4HANA_CHECK_ENABLE will then give you a list of items that require migrating before you get to SAP BW/4HANA. It's a comprehensive report that may contain a very large number of objects.
First, you need to figure out which of these objects are actually in use. In many cases, customers activate large amounts of business content which are never used and never deleted. My advice to you in this situation is to go ahead and delete all this. There may be projects which never went live and areas of BW which are no longer used. Check with the business and get permission to delete all that. We found this accounts for 50%+ off all BW objects.
Second, you need to convert any 3.x content to 7.x content. This might be straightforward (open queries in BEx 7.x, save them) or it might be more complicated (data flows etc.). If you have a lot of 3.x content, you might want to consider a new system. For InfoProviders, there is transaction RSB4HTRF which provides semantic object conversion.
Third, you work through the report piece by piece and convert the remaining objects. It's possible to do this in a Big Bang approach, or business content area by area, as projects allow. For large and complex systems, customers will take a more segmented approach.
Step 3 - Move to SAP BW/4HANA
Once you have upgraded the last object, report RS_B4HANA_ENABLE_CHECK will allow you to lock in BW/4HANA mode and no legacy objects can be created any more.
It is then possible to move to SAP BW/4HANA which will remove all the legacy AnyDB code and activate new BW/4HANA functionality.
Start with a fresh SAP BW/4HANA system
This might sound like an extreme approach but we're finding that a fresh system approach is something that will work well for certain customers. Here are some scenarios which might push you in this direction.
Large number of unsupported Add-Ons
Some Add-Ons, like BPC Embedded, are supported if you move to BW/4HANA (in fact BPC becomes part of the core NetWeaver 7.5 code line). Others like BPC Classic, require you to move to BPC Embedded.
Others, like SEM, aren't currently supported for BW/4HANA but we are expecting the SEM team to offer a removal tool and a new version of SEM for BW/4HANA which is based on the new objects.
Yet others aren't supported and there may not be a removal tool. It may be possible to ask SAP to manually remove an Add-On but in some cases there just may be no clear migration path to SAP BW/4HANA without a fresh install.
Large number of legacy 3.x objects
There are some semi-automated tools for BW 7.x objects today and SAP is working hard on improving the automation, with the eventual goal of a one-step process to get from BW 7.x to BW/4HANA.
BW 3.x ODS, transfer rules, queries etc., are more problematic because they require a conversion to BW 7.x objects and then BW/4HANA objects.
If you have a large number of these, the effort in migrating to BW/4HANA might be too high and you may need to consider a fresh install as a lower cost option.
Business needs have changed
Many BW systems are fifteen years old and the business needs may have changed around them. A simple example would be that line item detail for sales orders is required but was never loaded into BW.
If your existing BW system doesn't well fit your needs for tomorrow from a data perspective, you might consider leaving it where it is and starting with a new SAP BW/4HANA system and building out what the business needs.
The major advantage here is if there are specific business areas to focus on, you can do this in a new system, starting immediately, without having to complete a migration.
We recommend you take a close look at the system you've got and make a short comparison of your SAP BW environment as it exists today, what your Logical Data Warehouse needs are going forward, and what the right approach is for your organization.
If you're interested in a third party assessment, we have developed a methodology and BW/4HANA analysis tools to help make this decision with you. Get in touch with us for more details!