Customisation vs Configuration — the ERP Make-or-Break | ERP for Beginners S2 Ep1

Season Two of ERP for Beginners begins. This is the most important mental model in the whole ERP world — and it's the one people most often get wrong. Configuration means changing how the ERP behaves without writing any new code. Customisation means writing new code that didn't ship with the product. They sound interchangeable; they're not. Projects that understand the difference come in on time. Projects that don't, don't. A vendor-neutral, plain-English walk through what each term really means, why the industry is terrified of over-customisation, and how the modern "clean core" / extensions approach lets companies customise without paying the long-term tax. What You'll Learn: - What configuration actually means (chart of accounts, company codes, approval workflows, tolerance rules — the vendor's switches) - What customisation actually means (ABAP, Apex, SuiteScript, PL/SQL — writing code in the ERP's programming model) - The three horror-story costs of over-customisation: upgrade bills, support walls, and buried best practices - The grey zone — user exits, workflow engines, form designers — and the one test that matters: does it survive the upgrade? - When customisation is genuinely the right call: competitive difference, regulatory gaps, legacy bridges - The modern answer — extensions, clean core, side-by-side — where custom logic lives outside the ERP and talks through stable APIs Timestamps: 0:00 - Intro — the distinction that predicts project outcomes 0:19 - What's in this episode 0:45 - What configuration is — flipping switches the vendor installed 1:48 - What customisation is — writing code the vendor didn't ship 2:58 - The horror stories — why over-customisation kills projects 4:20 - The fuzzy line — user exits, workflow engines, custom fields 5:20 - When customising is actually right — three real cases 6:23 - The modern answer — extensions, not modifications 7:31 - Why this is the #1 mental model — it predicts outcomes 8:26 - Recap — config vs custom in four points 9:11 - Coming next in Season 2 Key Takeaways: 1. Configuration is flipping switches the vendor already installed — no new code, survives every upgrade. 2. Customisation is writing code that didn't exist in the shipped product — powerful, but expensive over the decade. 3. Projects that lean on configuration come in on time. Projects that lean on customisation overrun, accumulate technical debt, and pay for the same implementation twice at the next upgrade. 4. The industry mantra — "vanilla is best." Customise narrowly, document why, plan the exit. 5. The modern approach is extensions: keep the ERP core vanilla and write custom logic in a separate platform that talks through stable APIs. SAP calls this "clean core"; every vendor has their own name for it. Season 2 "Going Deeper" begins. Coming next — master data vs transactional data, following a transaction end-to-end, integration, multi-entity global setups, and the real cost of ERP. Taught by CelesteAI. Like and subscribe to catch the rest of Season 2.