Does SAP HANA Replace BW? (Hint: No.) – Part 2

John Appleby

Posted by John Appleby on June 20, 2012

Global Head Of DDM/HANA COEs

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Steve Lucas wrote a great blog this week entitled Does SAP HANA Replace BW? (Hint: No.). Given he covered at a high level a few of the dozens of possible scenarios applicable to BW and HANA, I thought I would address a few more. That and at the end of it he mentioned there would be a Part 2…so I immediately asked him if I could help him write it!

Sometimes I feel like people forgot why they implemented a Data Warehouse in the first place and therefore don’t see much value in it…which is concerning and a great place to start.

Q: Why did or might customers want to implement SAP BW?

By far the majority of SAP BW installations are for SAP ERP customers, many of whom wanted an Operational Data Store. We often call SAP an Enterprise Data Warehouse (EDW) but it is rarely used as one. The reasons for implementing it, however, are the same:

  • History. Retain historic information that you want to remove from your ERP environment.
  • Persistence. Integrate information from disparate sources, store it in one place and present a single view of the truth.
  • Performance. Remove load from ERP environments and aggregate data for good performance.
  • Dimensional Conformance. Retain same semantic meaning across process areas – of customer, supplier, product etc.

My supposition is that the reasons above are why customers deployed SAP BW. They may not understand or appreciate all those points, which is concerning! This brings to mind a few questions, comments I have about the legacy of BW and its future.

What’s the issue people have with SAP BW? It’s all about performance!

Steve gets into great detail in Part 1 of the blog, and the essence of it for me is that traditional RDBMS like Oracle or IBM DB2 haven’t provided what is needed. When organizations implemented SAP BW back in the early 2000s, the data volumes and complexity allowed simple Operational Data Warehouses to perform reasonably well when run on an OLAP database like Oracle.

We’ve had two issues working ‘against’ BW over the last decade:

1) Massive data volumes stored in BW, way beyond initial design. The BW product has gained new features and at the same time, data volumes ballooned and the use cases for BW increased dramatically, so organizations had packed much more information into BW than originally planned/modeled.

2) Performance expectations have moved from hours or minutes to real time. The rise of Google and the iPhone means that people expect information at their fingertips, without a wait.

Granted, the Business Warehouse Accelerator (BIA/BWA) goes some way to resolve the response times, but regardless, the problems of agility, adoption and load times remain, and BW has become bogged down by its own success.

What if I just use BW for one area? Will that help performance?

If this is the case, then you aren’t using BW as it was really intended. While that’s perfectly acceptable, there may be better options for you to consider. If you don’t need to derive the four main benefits of BW I mention above, then you have the complexity of a Data Warehouse without the benefits. Not good.

In this case a good approach would be to use HANA Enterprise without BW, which is an excellent database and data mart, using either SAP’s Direct eXtractor Connection (DXC) or System Landscape Transformation technologies as the ETL layer.

But watch out if you are in fact an extensive BW user and you decide to take this approach. Your first HANA standalone Data Mart project on HANA Enterprise will work great. However, when you come to a “second” project, you will end up with multiple Data Marts rather than an integrated solution – losing in the process a bunch of benefits that BW gave you, which you forgot you wanted.

It’s worth remembering as Thomas Zurek points out, “It’s not an either-or but an and”. You can have HANA Enterprise as a Data Mart, and BW on HANA as an Operational Data Warehouse. Have your cake and eat it!

What if someone has already invested in BWA?

Big shout out to Emma Moss for asking me this question. If a company has deployed BWA then they are already in a great position because they have experienced first-hand the benefits that in-memory computing can bring – to the reporting layer of SAP BW. (BWA/BIA is an In-Memory system, albeit different than HANA)

Let’s say you own BWA and Oracle, and want to migrate to a “HANA only” scenario. If you do, there are actually quite a few benefits:

  • Simplification into one single database – not one Oracle DB and a bunch of BWA blades.
  • The same great in-memory benefits to your Data Warehouse development and data loads.
  • Simplification of data models and cutting out of redundant layers. (DB Indexes, Aggregates, BWA Indexes, InfoCubes etc.)
  • Reuse of rather expensive mainframe BW hardware and commodity BWA blades into your IT landscape.

All that and SAP will typically provide a credit of your BWA purchase price towards your HANA purchase. It’s worth talking to SAP about that.

What if we are considering getting rid of BW because it’s too slow?

I talk to a lot of customers who are frustrated with BW and some of them have good reason to be frustrated. However, there is one key question to bear in mind if you are considering moving away from BW:

First and foremost…What would you move to? Steve puts some suggestions of what might be on your mind: Rapid Marts, Custom Build, etc. but they are fraught with challenges (see my points above). You have the same problem with replicating all the complex business transformations in another EDW like Cognos. Besides, are you sure that moving from BW to another traditional EDW platform is going to make things better?

What’s more – organizations spend millions, tens of millions or even hundreds of millions building out an EDW. Building out a new one will cost you the same again. Business Processes don’t magically simplify themselves because it’s 2012 vs. 2002.

BEFORE you decide that BW is “not right” for you, consider that swapping out your Oracle DB underneath and existing BW system for SAP HANA will cost a relatively modest amount of money compared to building out a new EDW, and the cost can be determined to a very high degree of accuracy early on. Once you get to BW on HANA – many of the objectives you had in mind…e.g. speed, performance etc. will be right there for you.

To add to that, you don’t have to undergo business change – the reporting tools can stay the same if you want them to – and you don’t have to have a long, expensive change freeze.

Oh, one more thing. SAP is so confident that you’ll be thrilled with BW running on HANA, they have a deal on the table: if you’re not happy with SAP HANA in 18 months, SAP will provide you with a license credit for another product.

Why do I need BW at all if I have DXC?

Thanks to Jan van Ansem for this question. You are absolutely right that the DXC technology – a mix of the ERP/BW Business Content Extractors and the Data Services product – allows you to use SAP Business Content and load that into almost any database. This is useful in some non-BW on HANA scenarios:

1) When/If you want a data mart. As with the scenario above, if all you wanted was a data mart anyhow, DXC gives you options of where you want to put it. I recommend SAP HANA Enterprise because it is awesomely fast and flexible, plus is comes with some RDS scenarios that include HANA content, but you could potentially use any other database including Sybase IQ, or a 3rd party EDW.

2) When you have an established EDW. If you have an established EDW and you only want a bit of ERP data then it may make sense to move this data into that EDW using DXC.

However if what you wanted was an EDW, then BW on HANA makes a whole lot of sense as that EDW – not any other platform. Why is this?

1) BW is the only EDW that provides the “other half” of Business Content. Whilst the SAP ERP Business Content Extractors provide one half of the business content (including the handling of delta changes), if you use any other EDW platform including Sybase IQ then you have to rebuild all the business transformations, structures, cubes, queries etc. that exist for free in BW. Don’t underestimate how much work this entails.

2) BW takes some serious heavy lifting away. Features like stock pointers, time-dependent master data, virtual cubes, MDX and SAP BusinessObjects integration etc. make BW a very compelling platform. Before you discount BW, make sure you know the effort required in modeling these in another EDW.

3) BW on HANA gives you what you wanted in the first place. When we combine BW with the power of the HANA Database, you get what you really needed: a powerful modeling platform with the agility and performance that you wanted.

Given Jan asked me this question, let’s address his valid/typical BW pain-points and discuss how BW on HANA might address them:

1) Point: BW can present complicated, long running load processes which are difficult to manage.

Counterpoint: BW on HANA allows you to collapse layers. With BW on HANA you lose Databases, Indexes, Aggregates, BWA indices and Dimension Tables on day one. This simplifies things, especially on BW 7.3 which has much better administration tools for loading. Plus, in the future, you can look at removing cubes altogether – depending on your scenario – and creating logical cubes rather than physical instantiations.

2) Point: A delay of one day is possible between when data is loaded in the transactional system and the data being available in BW reporting.

Counterpoint: BW on HANA allows you to combine realtime and batch data. You can load data into HANA using SLT in real-time and combine this with BW master-data if you want to, using Transient Provider technology. In addition, the reduced number of layers means that you can load more often.

3) Point: Business users complain about the reporting tools in BW. (BEx Analyzer, Query Designer, Web Application Designer)

Counterpoint: SAP is investing in the front-end and much of this is available today. The SAP BI4 platform – especially in the new FP3 release – is highly integrated for SAP HANA. What’s more there are two new awesome tools – SAP Visual Intelligence (Codenamed HILO), which is a desktop analysis tool and SAP Predictive Analysis, which is also a desktop tool but a business analyst-friendly SAS/SPSS competitor. And there is SAP Analysis Edition for Application Design (known affectionately as project Zen) coming later in the year, which replaces the Web Application Designer and will be mobile-friendly.

4) Point: The reality of poor performing reports.

Counterpoint: Hopefully I don’t need to tell you why BW on HANA fixes this! But, SAP is investing substantially into the future of BusinessObjects technology to make it integrate much more deeply with HANA – for example moving the front-end technologies of the BI platform and the Data Services ETL engine in-memory.

If one comes to the conclusion that BW on HANA is a good option, one will naturally have additional questions.

What will happen to ABAP in BW?

Thanks to Vivek for this question. The short version is: HANA is a database that replaces Oracle for the RDBMS on BW and the application layer works just like it did before (but better!), and that includes your existing ABAP.

In addition, stuff like the OLAP Engine, DSO Activation and Planning functions are pushed into the in-Memory HANA layer down from the ABAP engine. This makes them really fast.

Regular ABAP continues to run, against the HANA RDBMS. Or you can optimise it for HANA if you like, including using the powerful SQLScript Stored Procedure language run from ABAP – or alternatively just by rewriting your custom ABAP in transformations, DTPs, etc. to take advantage of the way that SAP HANA can process set-based SQL statements much faster than loops.

My advice: find slow-running custom ABAP and optimize it for SAP HANA, and leave the rest as it is. This way you get the maximum benefit for minimum work!


If you are an SAP ERP customer, need an analytics solution and asking the question: “Should I implement or move to SAP BW on HANA?” then I think the answer should be: Yes, unless you are one of the special cases above where you don’t need it.

Hopefully this Part 2 of the blog will necessitate Part 3 – but that’s up to you as to whether there are still scenarios and questions left unanswered!

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