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)

Disclaimer

This presentation focuses on the on Premise world …

… the Cloud is a completely different Story!

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

Recommendation #1: Read, Read, Read

• SAP changed quite some things in S/4HANA – make sure you knowhttps://help.sap.com/viewer/product/SAP_S4HANA_OVERVIEW/latest/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

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

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 reducesthe effort

• Tools can support you in this undertaking (e. g. UPL)

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 Extensibilityhttps://www.sap.com/documents/2015/07/2ad59b27-347c-0010-82c7-eda71af511fa.html

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 changeshttps://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

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 solutionson S/4HANA installations, provided customers have licensed the applicablesolutions 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/pdfac0fa9551dd88809f10000000b441570/1511%20000/en-US/CP_FAQ.pdf

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, Matchcodesand 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

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

Recommendation #7: Stick to the S/4 Programing Model

©SAP SE (TechEd 2016 DEV109)

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

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/bc687d35fa42ccbb0b9256ce786d51/frameset.htm

• Last but not least: TEST, TEST and TEST! Not everything will work out as expected

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

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)

Recommendation #9: Where to Start?

Recommendation #9: Where to Start?

Recommendation #9: Where to Start?

Challenges

• The base is still shaky, so leading edge is sometime bleading edgeBe 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

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

Thanks for your Attention!