Oracle Fusion Extension Architecture:  Choosing Between Fusion VBS, Standalone Visual Builder and Oracle Integration VBCS 

An architect’s decision framework for Oracle Fusion application extensions 

Introduction 

Oracle customers have several technologies available for extending or building applications around Oracle Fusion Cloud Applications, including Oracle Integration with Visual Builder, Standalone Oracle Visual Builder, and Oracle Visual Builder Studio for Fusion Application Extensions. 

One of the most common questions from customers is: “Which technology should we use, and in what situation?” The answer depends on the application’s relationship with the Fusion ecosystem, integration requirements, user population, data requirements, scalability, lifecycle management, and licensing model. 

1. Oracle Integration with Visual Builder 

Oracle Integration can provide Visual Builder capabilities as part of the Oracle Integration platform. This option is particularly useful when the application requires significant interaction with external systems, and the organization already has Oracle Integration available. 

Visual Builder applications can consume Fusion REST APIs as well as external REST services. Oracle Integration also provides integration, orchestration, transformation, monitoring, and connectivity capabilities. 

When should we consider this option? 

• The application has frequent interaction with multiple external systems. 
• Oracle Integration is already licensed and has sufficient messages based on message packs. 
• Integration logic, transformation, orchestration, or monitoring is an important part of the solution. 
• The application itself is relatively lightweight and does not justify provisioning a separate Visual Builder environment. 

Licensing consideration 

The licensing impact should be evaluated based on the Oracle Integration consumption model and Visual Builder usage. For Oracle Integration, message consumption depends on the applicable licensing model. Visual Builder usage within Oracle Integration also has its own metering rules like 100 messages consumption per session of the user. Therefore, the decision should be based on actual application usage and existing Oracle Integration entitlement rather than assuming a fixed message consumption per user session. 

2. Standalone Oracle Visual Builder 

Standalone Oracle Visual Builder is appropriate when the requirement is to build an independent application outside the Oracle Fusion Cloud Applications ecosystem. Unlike a Fusion Application Extension, the standalone application has its own application lifecycle and can be designed around its own users, security model, data requirements, and application architecture. 

Standalone Visual Builder is licensed based on provisioned OCPUs. 

When should we consider this option? 

• The application needs to operate independently of the Fusion user experience. 
• The application has users who do not have Fusion Cloud Application credentials. 
• The application requires its own security and application boundaries. 
• The application needs to integrate with multiple enterprise systems, and Fusion is only one of those systems. 
• The application has sufficient scale or usage to justify a dedicated Visual Builder runtime. 

The cost and required OCPU capacity should be determined based on the application’s expected workload and sizing requirements. It should not be assumed that Standalone Visual Builder is always the most expensive option; actual cost depends on the licensing and consumption model. 

3. Oracle Visual Builder Studio – Fusion Application Extension 

Oracle Visual Builder Studio is the preferred technology when the requirement is to extend an Oracle Fusion Cloud Application. It can be used to customize supported Fusion Redwood pages, create new App UIs/pages, consume Fusion REST APIs, consume supported external REST APIs, reuse Fusion security and application identity, and manage source code, Git repositories, and CI/CD pipelines. 

One of the major advantages is that the extension becomes part of the Fusion Cloud Applications ecosystem, rather than being an entirely separate application. 

When should we consider this option? 

• The application is primarily intended for Fusion users. 
• The application should be accessed through the Fusion ecosystem. 
• Fusion authentication and authorization should be reused. 
• The requirement is to extend an existing Fusion business process or user experience. 
• The custom application is relatively lightweight and closely related to Fusion functionality. 

External connectivity 

An important clarification is that Fusion VBS App UIs are not restricted to Fusion endpoints. Current Oracle documentation supports creating service connections to external REST APIs. The architectural question is therefore not simply whether an external endpoint can be called, but whether the required external connectivity, authentication mechanism, data processing, security model, and integration complexity are appropriate for an App UI. 

Data considerations 

For Fusion application data and custom business objects, Application Composer can be used where supported by the relevant Fusion application. Application Composer supports custom objects, fields, relationships, security, and REST exposure for supported objects. However, Application Composer should not be presented as a generic replacement for an external database. 

Cost and lifecycle 

VB Studio is provided as part of the Fusion Cloud Applications ecosystem, and Oracle documents the Fusion Applications identity domain as having no additional licensing cost for building extensions using that identity domain. Related OCI/build/storage services can, however, have their own costs. 

VB Studio also provides Git, CI/CD, code review, and development lifecycle capabilities. Therefore, for a lightweight Fusion-centric application, Fusion VBS can be a very attractive option from both an architectural and cost perspective. 

Architect’s Decision Framework 

The decision should not simply be based on which technology can build the UI. All three options can support application development to some degree. Instead, ask: “Where should the application belong?”