The transition from Oracle E-Business Suite (EBS) to Oracle Fusion Cloud Applications is a key milestone for organisations striving to embrace a cloud-first future. But this journey is rarely straightforward — especially when custom applications are involved.
Over the years, businesses have built numerous custom apps and extensions around EBS to address gaps, streamline operations, and meet industry-specific needs. As they move to Oracle Fusion — a SaaS platform that promotes configuration over customisation — these legacy solutions often become blockers unless modernised in parallel.
How Prevalent Are Custom Applications in EBS?
While specific figures vary, industry estimates and experience suggest that between 60–80% of Oracle EBS customers have built custom applications or integrations. In sectors like construction, manufacturing, logistics, healthcare, or the public sector, this percentage can be even higher due to more complex operational and compliance requirements.
These apps typically handle tasks like:
- Advanced data entry and validation
- Approval workflows
- Third-party system integrations
- Custom reports and reconciliation processes
As these systems become embedded in daily operations, replacing them becomes a challenge — particularly when migrating to a more standardised SaaS solution like Oracle Fusion Cloud.
The Challenge: What Happens to These Applications in Fusion?
Unlike EBS, Oracle Fusion discourages deep customisations within its core environment. It provides a modern, API-first architecture designed for scalability and continuous updates. This creates several implications:
- No direct database access: Legacy apps that depended on EBS schema access won’t function in Fusion.
- Custom forms and workflows can’t be ported directly and must be rebuilt.
- Point-to-point integrations must be redesigned using REST APIs or middleware tools like Oracle Integration Cloud.
- Security roles and access controls differ significantly, creating potential risks during the transition.
- Data structures and logic may need transformation, increasing migration effort and complexity.
Without a strategy for handling these custom applications, organisations risk operational disruption or costly delays in adoption.
The Solution: A Dual Approach with APEX and VBCS
To retain critical business capabilities while aligning with the principles of SaaS, Oracle provides two powerful low-code platforms:
- Oracle APEX (Application Express)
- Oracle Visual Builder (VBCS)
These platforms allow businesses to rebuild or extend custom functionality outside the core Fusion environment, using secure, scalable cloud-native services that integrate seamlessly with Oracle Fusion Applications.
Oracle APEX: Rebuilding EBS-Era Applications on a Modern Platform
Oracle APEX is a low-code development environment that enables the rapid creation of web applications using Oracle Autonomous Database. It is especially well suited for data-centric applications, dashboards, and internal business tools.
Key benefits of APEX include:
- Rapid development using low-code tools
- Native integration with Oracle databases and REST APIs
- Modern, mobile-ready user interfaces
- Robust security and user access control
- Built-in reporting and data visualisation
APEX is ideal for rebuilding operational apps such as data loaders, reconciliations, approval forms, and internal reporting tools. It allows organisations to preserve critical functionality without embedding it in the Fusion core — maintaining clean upgrade paths.
Oracle VBCS: Creating Extensible, Fusion-Integrated Applications
Oracle Visual Builder (VBCS) is a powerful low-code platform tailored for building SaaS-integrated web and mobile applications, particularly where tight integration with Oracle Fusion is essential.
Key benefits of VBCS include:
- Built-in Fusion Application integration
- Design-first, drag-and-drop UI builder for modern apps
- Support for mobile and responsive design
- Use of standard JavaScript, HTML5, and Oracle JET under the hood
- Direct consumption of Oracle SaaS REST APIs
- Deployed securely on Oracle Cloud Infrastructure
VBCS is best used when organisations need to extend or augment Fusion Applications — for example, adding new screens, extending workflows, or capturing additional data that isn’t handled natively within Fusion.
How eAppSys Supports Application Modernisation
At eAppSys, we guide enterprises through the process of identifying, rebuilding, and integrating their EBS-era custom applications using the most appropriate tools for their use case — whether that’s APEX, VBCS, or a combination of both.
Our approach includes:
- Custom App Discovery & Assessment We catalogue existing EBS customisations and map them against available Fusion functionality to determine:What can be retiredWhat can be configured within FusionWhat should be rebuilt in APEX or VBCS
- Modern Architecture Setup We help clients establish secure, scalable environments for APEX and/or VBCS, including development standards, governance, and lifecycle management.
- Rebuild and Redeploy Our developers reimagine legacy functionality as modern applications — improving usability, enabling cloud scalability, and integrating tightly with Oracle Fusion via REST APIs.
- Integration Enablement Using Oracle Integration Cloud (OIC), we connect custom apps and Fusion seamlessly, ensuring real-time data flow and secure interactions.
- Accelerators and Pre-built Templates eAppSys brings a set of reusable components and frameworks that accelerate delivery of common use cases like onboarding, reconciliation, approvals, and reporting.
The Outcome
By embracing APEX and VBCS as part of their modernisation strategy, organisations can transition to Oracle Fusion Cloud without sacrificing the bespoke capabilities that drive their business forward.
These tools offer the flexibility to support unique processes outside the core SaaS environment, while preserving the integrity, upgradeability, and security of the Fusion platform.
eAppSys helps bridge the gap between legacy and innovation — enabling a smoother, smarter, and more value-driven Oracle Cloud journey.
Let’s Talk
If you’re planning a move to Oracle Fusion or are evaluating the future of your custom EBS apps, we’re here to help. Book a free consultation to discuss your needs with our experts.
