Planning for Tomorrow Today
Operational Reporting with Hana Live or Embedded Analytics?
Companies looking to migrate their SAP Business Suite to S/4 will also need to rethink the technology behind their existing reporting applications. Operational reporting with Hana Live is the solution of choice for SAP’s Business Suite powered by Hana. S/4, however, relies on Embedded Analytics and is built on a very different technological foundation. What does this mean for the customer? What do they need to keep in mind in order not to jeopardize the operation of their in-house developments?
SAP started shipping Business Suite powered by Hana back in May 2013, giving its customers overall improvements in performance and streamlined business processes based on Fiori applications. At the time, it also introduced Hana Live and with it high-performance analytics of available data from within the Hana database – the birth of operational reporting. Some media outlets already began to enthuse about an SAP R/4. But anyone who looked a bit closer soon realized that this was far from being a fundamentally new Business Suite. Both the data model and a number of its sometimes obsolete features remained firmly in place to ensure backward compatibility. This made it easy for existing Business Suite customers to migrate to the new product without having to sacrifice their in-house developments.
SAP S/4HANA, however, was a much bolder step for SAP that also prompted it to finally dispose of any legacy Business Suite functionality that was no longer needed. To improve performance, for example, it did away with tables that included pre-aggregated data. These are no longer needed on a platform like S/4HANA that delivers the performance required to instantly calculate the information at hand. It is indeed a genuine next-generation Business Suite. Customer migrating to S/4HANA need to be aware of this, because they will not be able to simply continue to run their in-house developments on S/4HANA.
Hana Live on S/4HANA
SAP customers that use systems powered by Hana are automatically granted free access to Hana Live content. Operational reporting solutions that build on this foundation combine a Hana-based virtual data model with a user interface based on SAP UI5 to analyze basic key figures from a wide variety of applications. As with BI content, the content provided by SAP also serves as a template for customer-specific enhancements. It is also possible to add new key figures or characteristics to the virtual data model and user interface and to customize the calculation logic for existing key figures.
But companies should be careful when migrating to S/4HANA. Here, operational reporting is based on Embedded Analytics rather than on Hana Live. While it is just as flexible, Embedded Analytics does not run on the same technology. As opposed to the virtual data model in SAP Business Suite on Hana, which relies exclusively on database tools (Hana Information Views), the Operational Reporting in S/4HANA is based on CDS views (Core Data Services), which are defined on the application server. (For an overview of the main differences between the two solutions, read the article “SAP BW – A Relic of the Past?”, the German version of which was published in the October issue of E-3 Magazine.) Hana Live developments can no longer be used due to the revised data model in S/4HANA and there are no plans to adapt Hana Live to S/4HANA. They are two completely separate operational reporting solutions intended for different SAP products.
Alternative 1: Don’t migrate, integrate
It is, however, still possible to continue to use Hana Live on S/4HANA. Customers can make the necessary adjustments to the virtual data model using customer enhancements. A strategy that can be worth the while for customers who have already invested time and effort into expanding Hana Live with in-house developments. This option of having the customer manually adjust Hana Live Views is considered a valid alternative by SAP. This, however, requires them to thoroughly review the individual changes that were applied to data model. SAP has compiled a Simplification List for S/4HANA (https://help.sap.com/s4hana_op_1511), which provides a good starting point.
One example: In the Business Suite, the table VBBS contained aggregated values on total sales requirements that were updated daily. Following the principle of doing away with aggregates, S/4HANA now directly accesses the individual requirements in table VBBE. It is possible, though, to configure and reverse this behavior. Table VBBS continues to exist in S/4HANA, but would normally not contain any data. Since the table is still available, the Hana Information Views that access this data are still allowed, even though they will not display any results anymore. Another example are the totals tables and index tables in FI-CO. These tables were deleted in S/4HANA. The data in the same structure, however, can still be accessed using ABAP views of the same name. SAP Note 1976487 explains this and other cases of changes to data models and contains instructions on how to proceed. What it does not do, however, is explain the changes to the Hana Information Views that may become necessary.
The data model was also changed on the level of individual receipts and master data, which are the preferred sources of data for Hana Information Views. For example in Controlling: The “Universal Journal” (table ACDOCA) combines a variety of tables with line items for operational reporting and planning purposes. The corresponding accounting document headers are stored in the table BKPF. This, however, does not apply to the Controlling component. The account document headers for the Controlling component are currently stored in table COBK, but SAP plans to change that with future releases of S/4HANA.
These examples show that developing your own Hana Information Views and making changes to S/4HANA requires deep knowledge of the data sources if you intend to continue to base your operational reporting on Hana Live after moving to S/4HANA. And then there is the need to analyze the impact of potential data model changes introduced with future updates.
Alternative 2: Hana Live on Embedded Analytics
Mutual access to Hana and CDS views is another technically feasible option and is particularly interesting for companies looking to expand on their in-house developments for Hana Live. CDS views already make up a large portion of the S/4HANA data model and are by no means limited to data that serves analytical purposes. Generally, a corresponding database view is created for each CDS view. These database views can be leveraged as a source for a Hana Calculation View.
The virtual data model in Hana Live enriches the table data with metadata (e.g. the assignment of total fields and currency fields, the number of decimal places, aggregation rules, etc.). Taking this approach means that all of this metadata will be completely lost and will have to be re-defined – this, however, does not apply to calculated key figures and the unions and joins that were already created for the underlying tables. It is also important to keep in mind that CDS views, just like Hana Information Views, are structured hierarchically. Bottom-level views are directly based on individual tables, which, however, could become obsolete in future releases. It would therefore be advisable to use parent views as a basis (e.g. CDS cubes). These will continue to exist under the same name and have similar and compatible content.
Alternative 3: Embedded Analytics on Hana Live
One point of criticism about Hana Live is the need to implement a new authorization concept from scratch. This solution, which builds exclusively on the database, requires customers to re-implement authorizations based on analytic privileges. When using Abap CDS views in S/4HANA, however, they can use the authorization objects of the application server. Customers looking to take advantage of this will continue to implement their table accesses and data formatting using Hana Information Views and then access the formatted data with CDS views. In this scenario, too, all metadata will be completely lost, but can be re-defined on the CDS level.
Like many other databases, Hana comes with its own set of SQL commands with Hana-specific commands. This so-called “native SQL” also allows access to Hana Information Views. Regular Abap code does not support this, because it relies on a reduced set of standard commands (Open SQL). The “Abap Managed Database Procedure” (AMDP) provides a workaround for this. With it, it becomes possible to execute native SQL commands on Hana and then use their results. This AMDP can then be defined as a “table function for CDS views”, which means it can be used as a data source for CDS views. Ultimately, what this does is that a CDS view no longer obtains its data from a table, but directly from a Hana view through native SQL.
There is another way to benefit from this approach: It is a little-known fact that Hana Live can also be used in a sidecar scenario. This refers to a system landscape in which Hana functionality is leveraged by initially replicating the relevant data from an AnyDB system to a separate Hana database, making it possible to incorporate the Hana Live content of another system into the CDS view-based reporting in S/4HANA.
What this also does is bring out the best in both technologies: Key figures are calculated on the database only, making the process highly efficient, while CDS views ensure that relevant information can still be accessed based on the Abap authorization concept and SAP system users.
SAP offers two operational reporting solutions. Hana Live is available for systems that run on SAP Hana and is based on Hana Information Views. S/4HANA, on the other hand, relies on Embedded Analytics, which, in turn, is based on CDS views. Customers that are already using standard Hana Live content ordinarily will not encounter any problems when switching to Embedded Analytics. If, however, they have implemented customer enhancements for their Hana Live content, they will not be able to simply migrate them.
The alternatives presented in this articles presuppose a deep understanding of the SAP data model, of Hana Information Views, and of CDS views. If used right, these can accelerate the migration of operational reporting when switching to S/4HANA. Depending on the method chosen, it is even possible to achieve performance improvements that go beyond SAP’s S/4HANA standards by more strongly shifting calculations to the database.
by Steve Blum, Consultant at Camelot ITLab
The original article was published in E-3 DEZEMBER 2016 / JANUAR 2017.