---
title: "SAP S/4HANA Alternative: Custom-Built ERP by ERPStack"
description: "Feature-by-feature comparison of SAP S/4HANA against a custom-built ERPStack system: licensing, lock-in, customization limits, and migration path."
canonical: https://erpstack.io/alternatives/sap
markdown_url: https://erpstack.io/alternatives/sap.md
publisher: ERPStack
---

# SAP S/4HANA vs. a custom-built ERPStack system

**Typical SAP S/4HANA license cost:** $100,000 - $1,000,000+ / year (2026 list pricing)
**Lock-in risk:** Extreme (ABAP ecosystem, complex upgrade lockouts)
**Modularity:** Very Low (Complex database dependencies, legacy tables)
**Customization ceiling:** Highly rigid (Requires multi-month custom consulting cycles)
**Migration path:** Headless API encapsulation and progressive microservices extraction

## Feature comparison

| Feature | ERPStack (custom) | SAP S/4HANA |
| --- | --- | --- |
| Deployment Speed | Days/Weeks (Vercel Edge) | Months/Years (On-prem or SAP Cloud) |
| Developer Ecosystem | TypeScript / React / Node.js | ABAP / Proprietary SAP tools |
| Real-time Analytics | Embedded with ClickHouse/Materialize | Requires separate SAP BW/4HANA instance |
| Open Source Standard | Yes | No |
| Manufacturing & Plant Maintenance (MRP/CMMS) | MRP runs and CMMS maintenance scheduling engineered to your shop-floor requirements, with job costing for construction and project-based operations | PP and PM modules each licensed and configured separately |
| Business User Experience | Role-specific React dashboards sized for the mid-size firm; user management and free read-only seats included | SAP GUI/Fiori access licensed per named user |
| Software Selection & Reviews | One 2-week expert requirements audit replaces months of comparing vendors — the benefits and trade-offs land in a management-ready decision document | RFP cycles across analyst reviews, demo scripts, and integrator options |

## Migration timeline

- **Strangler Fig Pattern Setup** (4 Weeks): Deploy API gateway to proxy requests between legacy SAP and new microservices.
- **Module Extraction** (3-6 Months): Extract domains (e.g., HR, Inventory) one by one — phase 2 of the four-phase implementation timeline.
- **Data Lake Sync** (Continuous): Real-time replication from SAP HANA to PostgreSQL via Debezium.
- **Decommissioning** (Final Month): Turning off the legacy SAP modules permanently after 30 days of clean parallel-run validation.

## Hidden costs of SAP S/4HANA

- **Consulting Fees:** SAP requires certified integrators. Minor UI changes can cost $50k+ in consulting hours.
- **HANA Memory Costs:** In-memory databases are incredibly expensive for cold/archival data. A custom build keeps hot data in PostgreSQL and archives cold records to object storage at a fraction of the per-GB cost — typically over 10x cheaper.
- **Service & Support Tiers:** SAP Enterprise Support lists at 22% of license value annually, whether or not you open a ticket. A custom system carries a flat service retainer the business can scale down or cancel after the switch.
- **Software Evaluation Cycles:** Choosing between S/4HANA editions consumes months of vendor research, user reviews, and integrator options before any build starts. Hire one team instead: a fixed 2-week requirements audit produces a management-ready decision document.

## Why teams leave

- Reduced deployment times from 6 months to 1 week by migrating HR modules away from SAP to a custom Next.js stack. (A third-party logistics operator — Inflexible UI and massive upgrade consulting costs.)