Talk at sitFRA 2017 by Tobias Trapp and Christian Lechner

1. ABAP Development in time of S/4
Do's and Don'ts and Golden Rules
for Simplification
Christian Lechner (msg systems)
Tobias Trapp (AOK Systems)

3. Disclaimer
This presentation focuses on the on Premise world …
… the Cloud is a completely different Story!

4. Simplification - It Is All About Business
• Rethink your business process
• Ask yourself: Are those processes really a differentiator?
• Check simplified processes of S/4HANA and get rid of redundancies
• No idea about the future of your business … you are not yet ready for
the journey 

5. Recommendation #1: Read, Read, Read
• SAP changed quite some things in S/4HANA – make sure you know
https://help.sap.com/viewer/product/SAP_S4HANA_OVERVIEW/late
st/en-US
• Starting point: SAP S/4HANA Requirements for Partner Solutions On
Premise Guide
• Insights on:
▪ Performance
▪ Extensibility
▪ Software Lifecycle
▪ Architecture
https://uacp2.hana.ondemand.com/viewer/product/SAP_S4HANA_ON-PREMISE/1610%2520000/en-US

6. Recommendation #1: Read, Read, Read
• Another Source for Information: SAP Community
(well .. if you find the things )
• Read the S/4HANA blogs on SCN
• Topics:
▪ S/4HANA Transformation Options
▪ Business Partner Approach
▪ Material Field Length Extension
▪ Data Model Changes in SD Pricing
▪ Output Management

7. Recommendation #2: Book Keeping
aka “He is Dead, Jim”
• Clean up your code base and remove unused and obsolete code
• Every line of code you do not have to check for compatibility reduces
the effort
• Tools can support you in this undertaking (e. g. UPL)

8. Recommendation #3: Learn about Extension
Mechanisms
• SAP clearly defined the extension mechanisms for S/4HANA:
▪ InApp Extensibility
▪ Side-by-Side Extensibility
• Make sure you know and use them in case you do extensions
• Starting Point: Whitepaper on Extensibility
https://www.sap.com/documents/2015/07/2ad59b27-347c-0010-
82c7-eda71af511fa.html

9. Recommendation #4: Go Compatible
• SAP changed the code, the data model and the processes in S/4HANA
… your code will propably need adoption
• Simplification List describes the changes
https://archive.sap.com/documents/docs/DOC-70833
• SAP tries to make the transition smooth
▪ Best practices and automatic checks for custom code in S/4HANA on-
Premise: https://archive.sap.com/documents/docs/DOC-70449
▪ Data models are being simplified – read access still possible via CDS
compatibility views

10. Recommendation #4: Go Compatible
• Temporal bridge to quickly bring you to the S/4 world: Compatibility Pack
• OSS note 2269324 - Compatibility Scope Matrix for S/4HANA on-premise:
Through the Compatibility Packages listed in the attachment ("matrix"), SAP
provides customers a limited use right to run certain classic SAP ERP solutions
on S/4HANA installations, provided customers have licensed the applicable
solutions as set forth in their license Agreements. This use right expires on
Dec 31, 2025, and is available to installed-base as well as net-new customers
• FAQ on Compatibility Pack:
https://uacp.hana.ondemand.com/http.svc/rc/DRAFT/pdfac0fa9551dd8880
9f10000000b441570/1511%20000/en-US/CP_FAQ.pdf

11. Recommendation #5: Use Modern ABAP
• SAP is deleting legacy code:
▪ Keep control about dependencies
▪ Use the ABAP package concept
▪ Think in terms of APIs
• Don’t use blacklisted technology like Logical Databases, Batch Input, Matchcodes
and everything what SAP does not recommend
• Don’t use techniques that prevent code scanning
• Use SCI/ATC checks  Think in Continuous Integration
• If not using Eclipse yet … now you really have to make the switch

12. Recommendation #6: Follow the Principle of One
• SAP avoids redundancy for frameworks and technologies
• So far the strategic frameworks have not been published with exception of
SAP HANA, BRFplus and Fiori
• SAP is still investing in established frameworks:
▪ Business Workflow
▪ Business Application Log
• Further recommendations by SAP:
▪ Adobe Forms for output management (OSS note 2228611)
▪ Document management: SAP presented their strategy at DSAG
Technologietage 2017

13. Recommendation #7: Stick to the
S/4 Programing Model
©SAP SE (TechEd 2016 DEV109)

14. Recommendation #7: Stick to the
S/4 Programing Model
• It all starts with data model:
Capture business intent and create a data model close to conceptual
thinking
• Create views using ABAP CDS views
• Implement code pushdown preferable CDS views e. g. :
▪ Unit, date/time or currency conversion
▪ Arithmetical expressions
• Define business logic using BOPF
• Generate BOPF objects and implement actions and validations

15. Recommendation #7: Stick to the
S/4 Programing Model
• Expose BOPF and CDS views via Odata/Gateway
• Create Fiori apps on top
• See also:
https://help.sap.com/saphelp_nw751abap/helpdata/en/d9/bc687d3
5fa42ccbb0b9256ce786d51/frameset.htm
• Last but not least: TEST, TEST and TEST!
 Not everything will work out as expected

16. Recommendation #8: Data Model is the Backbone
• Spend effort on your data model:
▪ Capture business intent and create a data model close to
conceptual thinking
▪ Use DDD
▪ Use meaningful and readable names for attributes
• Embrace the column-based data store of SAP HANA: Denormalize
• Zero redundancy:
▪ Don’t materialize views
▪ Don’t keep redundant attributes – join them using CDS views

17. Recommendation #8: Data Model is the Backbone
• Avoid generic structures in you data model:
▪ Name-value pairs
▪ Blobs containing complex data types
• Use GUIDs for primary keys (Makes life easier in BOPF)

18. Recommendation #9: Where to Start?

19. Recommendation #9: Where to Start?

20. Recommendation #9: Where to Start?

21. Challenges
• The base is still shaky, so leading edge is sometime bleading edge
Be aware of that!
• Information about (new) SAP frameworks is limited
• SAP does not always eat its own dog food
e. g. Industry Solutions vs. S/4 paradigms
• Transformation of old code can be a challenge e. g. harmonization of
LUW concepts of legacy applications and BOPF transaction manager

22. Challenges
• Product Development: Move to S/4HANA means Code Split!
 Depending on your strategy you might have 3(!) lines of code for a
certain time

23. Thanks for your Attention!