SAP Middleware comparison: CPI vs. PO

There are some blog posts existing about comparing SAP´s Middleware Solutions from an architectural perspective:

• On-Premise: SAP Process Orchestration (PO), with SAP PI, SAP BPM, SAP BRM
• Cloud: SAP Cloud Integration (as part of SAP Integration Suite), fka. HCI, CPI

Now, from a functional/development <interface design> point of view here are the highlights:

1. Flexible Pipeline
   • PO: Very standardized approach of an iFlow/ICO: Connectivity-> Routing-> Mapping-> Connectivity.
   • CPI: Completely flexible approach. Provides transparency about all processing steps (conversions, routing, transformation, security elements).
2. Stateful Message Processing
   • PO: Mainly part of BPM.
   • CPI: Integrated in iFlow already. In addition there is a powerful Data Store to persist data.
3. Human Tasks
   • PO: Part of BPM.
   • CPI: Not integrated, this is addresses with SAP Cloud Platform Workflow.
4. Separation of Design Time & Configuration
   • PO: ESR for design time artifacts, DIR for configuration.
   • CPI: Mainly managed in the iFlow. Configurable Elements can be externalized, Users are managed also outside of iFlows.
5. Interface Modeling
   • PO: Interfaces can be modeled with data type editors and using GDTs => Outside-In approach (Inside-Out also possible).
   • CPI: No modeling environment available. (Existing) interface definitions (WSDL, XSD) have to be imported => Inside-Out approach only. Import of ESR Objects (Service Interfaces, Mappings) possible.
6. Content Organisation & Reuse
   • PO: Strong governance enables reuse of integration content globally.
   • CPI: Each iFlow is autonomous, lean and independent. Reuse exists for user credentials though. Using the ProcessDirect Adapter, certain functionality can be centralized. Since Q2/2021 also Scripts and Mappings can be reused.
7. Asynchronous Messaging
   • PO: Guaranteed delivery in EO/EOIO mode
   • CPI: By default only “Transient Cloud Messaging”. EOIO not available, EO must be modeled manually using Data Store or via JMS (since Q4/2018 not only in Enterprise Edition), some adapters provide queueing though. See Best Practices.