ATC, Custom-Code Migration & Simplification

• QuestionWhat is "ATC variants every team should know"?Tap to revealAnswerThe ATC variant you choose defines what 'clean' means — know the SAP ones (readiness, cloud, performance, security) and build one tuned union for your team.
• QuestionIn "ATC variants every team should know", explain:Tap to revealAnswerDEFAULT is broad and release-agnostic — not Clean Core or readiness aware.
• QuestionIn "ATC variants every team should know", explain:Tap to revealAnswerS4HANA_READINESS_<year> = Simplification + HANA readiness; the suffix tracks the TARGET release (use S4HANA_READINESS_2025 for S/4HANA 2025; 2023 is the prior-release variant).
• QuestionIn "ATC variants every team should know", explain:Tap to revealAnswerABAP_CLOUD_DEVELOPMENT_DEFAULT = ABAP Cloud readiness (Restricted ABAP, released-only); ABAP_CLOUD_READINESS measures 'distance to Tier 1' for baselining legacy code.
• QuestionIn "ATC variants every team should know", explain:Tap to revealAnswerABAP_CLEAN_CORE_DEVELOPMENT (new 2025, BTP ABAP env + S/4HANA 2025 FPS01+) = clean core readiness, grading against Levels A–D, not pass/fail.
• QuestionAnalogy for "ATC variants every team should know":Tap to revealAnswerVariants are different inspection checklists for the same building — pick the right checklist for the question you're asking, or staple the relevant ones into one house standard.
• QuestionWhat is "ATC topology: local, central, CI/CD"?Tap to revealAnswerRun ATC three ways — locally in ADT for fast feedback, centrally over RFC (where the Simplification DB and baselines live) as the real setup, and in CI/CD via the Code Inspector API.
• QuestionIn "ATC topology: local, central, CI/CD", explain:Tap to revealAnswerLocal ATC: per object/package in ADT — fast inner-loop feedback.
• QuestionIn "ATC topology: local, central, CI/CD", explain:Tap to revealAnswerCentral/remote ATC over RFC against source systems is the production setup.
• QuestionIn "ATC topology: local, central, CI/CD", explain:Tap to revealAnswerThe Simplification DB lives centrally on the ATC master — one current catalog for all systems.
• QuestionIn "ATC topology: local, central, CI/CD", explain:Tap to revealAnswerCentral ATC owns baselines and the exemption workflow (one governance point).
• QuestionAnalogy for "ATC topology: local, central, CI/CD":Tap to revealAnswerLocal ATC is a spell-check as you type; central ATC is the editorial desk with the master style guide; CI/CD is the automated gate that won't publish until the desk signs off.
• QuestionWhat is "The exemption baseline"?Tap to revealAnswerA baseline freezes today's findings as accepted debt so ATC only flags new debt — and it can be transported so the whole landscape shares one line.
• QuestionIn "The exemption baseline", explain:Tap to revealAnswerA baseline snapshots today's debt so ATC warns only about NEW debt.
• QuestionIn "The exemption baseline", explain:Tap to revealAnswerWorkflow: run → Create Baseline → future runs show only deltas.
• QuestionIn "The exemption baseline", explain:Tap to revealAnswerMaintain or re-baseline as you fix findings so accepted debt only shrinks.
• QuestionIn "The exemption baseline", explain:Tap to revealAnswerBaselines can be transported across systems, so the whole landscape shares one line.
• QuestionAnalogy for "The exemption baseline":Tap to revealAnswerIt's marking the existing scratches on a rental car at pickup, so you're only charged for new ones you cause.
• QuestionWhat is "The full Custom Code Migration loop"?Tap to revealAnswerMigration is a loop: scope by usage (SCMON/SUSG), scan with the readiness variant, prioritise by used × standard-impacting × cost, rewrite to released APIs, and re-baseline each sprint.
• QuestionIn "The full Custom Code Migration loop", explain:Tap to revealAnswerScope by usage first: SCMON for what runs, plus SUSG for multi-system roll-up.
• QuestionIn "The full Custom Code Migration loop", explain:Tap to revealAnswerQuality scan: ATC S4HANA_READINESS_2023 remotely against the source, then export findings.
• QuestionIn "The full Custom Code Migration loop", explain:Tap to revealAnswerPrioritise on used? × standard-impacting? × cost — fix high-value items first.
• QuestionIn "The full Custom Code Migration loop", explain:Tap to revealAnswerAdapt to released APIs; exempt only where the rewrite cost is unjustified this cycle.
• QuestionAnalogy for "The full Custom Code Migration loop":Tap to revealAnswerLike renovating a house room by room — first find which rooms you actually live in, inspect those, fix the worst-and-cheapest first, and re-survey after each phase.
• QuestionWhat is "High-impact Simplification Items"?Tap to revealAnswerA few data-model changes (konv→prcd_elements, mseg+matdoc, bseg→acdoca, nast→Output Management) have the greatest impact — bridge old reads with the released I_* interface views (e.g. I_OperationalAcctgDocItem).
• QuestionIn "High-impact Simplification Items", explain:Tap to revealAnswerPricing konv → prcd_elements; inventory mseg augmented by matdoc.
• QuestionIn "High-impact Simplification Items", explain:Tap to revealAnswerFI document bseg → the universal journal acdoca.
• QuestionIn "High-impact Simplification Items", explain:Tap to revealAnswerOutput management nast → the new Output Management framework.
• QuestionIn "High-impact Simplification Items", explain:Tap to revealAnswerDirect reads often still work on 758 but miss the new source of truth — the danger is silence.
• QuestionAnalogy for "High-impact Simplification Items":Tap to revealAnswerThe old address still gets some mail, but the household has moved — forward your reads through the released interface view to reach the real, current data.

1. 1Summarise the core idea

   Analyse~10 min

   In your own words, summarise the central idea of "ATC variants every team should know". Aim for one paragraph, no jargon you haven't earned.

   Done when: A non-expert could read your paragraph and explain it back to you.

   Re-read the source concept

2. 2Use it to a real situation

   Apply~15 min

   Find a real situation from your own work / life where "High-impact Simplification Items" applies. Use the idea — describe the situation, the move you'd make, and the alternative you considered first.

   Done when: You can name a specific situation (not a hypothetical), state your move, and explain the trade-off in one paragraph.

   Re-read the source concept

3. 3Teach it back

   Evaluate~5 min

   Pick someone (a colleague, a peer, a rubber duck) and explain the section to them in under 5 minutes. Use your own example, not the one from the lesson.

   Done when: Your listener can repeat the core idea + the trade-off back to you without prompting.

Why this matters. Reading + quizzing prove recall; applying it in a real situation is the only evidence of transfer. Treat at least one of these as non-negotiable before you move on.