1. What?
   1. An architectural (custom code) strategy and approach to smooth future upgrades - allow customisations that need to be carried over from one version of SAP to another.
   2. One of the biggest technology headaches & ROI killer that CIOs face in upgrades e.g. to S/4 HANA
   3. Clean Core Principle is about the separation of standard code from custom code and has been introduced to enable release stability as well as a transition to a public cloud deployment option
2. Why?
   1. Increase innovation pace - faster upgrades mean better features.
   2. Smooth future upgrades
   3. Create sustainable changes with fewer "breaking changes"
3. How?
   1. Analyse your existing custom code & associated usage metrics
      1. SAP Standard Tools
         1. SAP Custom Code Analyser
         2. SAP Intelligent custom code management (packaged service)
      2. 3rd Party Accelerators
   2. Three key approaches (3R strategy)
      1. Retire
         1. Sunsetting existing applications
         2. No longer in use, or because standard functionality is now available to meet need.
      2. Refactor
         1. Adjust your custom code to continue to run it in the new (S/4) environment.
         2. Rebuild into a cloud programming paradigm
      3. Rebuild
         1. Redesign critical innovations and extensions and put them on a more future proof platform.
   3. SAP Provided capabilities
      1. Key user "in-App" extensibility
      2. Developer "on-stack" extensibility
      3. Side-by-side extensibility with BTP
      4. See decision matrix on Pg61
4. Links & Articles
   1. Intelligent Custom Code Management (Blog)
   2. SAP Mission: Use SAP Fiori Custom Code Migration App to Analyze Your ABAP Custom Code for SAP S/4HANA Readiness
   3. Custom Extensions in SAP S/4HANA Implementations - A Practical Guide for Senior IT Leadership (PDF)
   4. SAP S/4HANA Extensibility Options For Clean Core Journey
   5. Bringing Together Clean Core, Cloud, the SAP Extension Suite and SAP BTP: A Clean Core and Differentiation / Extensibility Strategy
   6. Custom code analysis for SAP S/4HANA with SAP Fiori App Custom Code Migration
   7. Clean Code Overview Video (SAP)
   8. "Keep the core clean" statement considered harmful
5. 3rd Party Accelerators
   1. Analyse
      1. Smartshift
         1. Automate code remediation
      2. ITAG
         1. Introspect config & custom development to make porting and support easier
   2. (re)Build
      1. BettyBlocks
         1. Innovation platform to build apps, automate processes, and increase efficiency
      2. Neptune Software
         1. Rapid App Development
      3. Pillir
         1. Low-code solution is the only rapid application platform that automatically modernizes your legacy SAP applications
      4. Mendix
         1. Low-Code enterprise app development
      5. Fuse
         1. Connect SAP Data & Microsoft Dataverse
   3. Automate
      1. UIPath
         1. Automation platform
      2. BettyBlocks
         1. Innovation platform to build apps, automate processes, and increase efficiency
      3. Siamese
         1. Automation test tool
6. Mind Map by Warren Eiserman September 2023