Häufig gestellte Fragen
What is the difference between EAI and iPaaS?
EAI refers to the overarching discipline of application integration and was traditionally implemented on-premises via middleware or an enterprise service bus, while iPaaS (Integration Platform as a Service) describes the cloud-based delivery model for the same task. In substance, both solve the same problem — enabling ERP, CRM, warehouse management and other applications to communicate with each other reliably — so iPaaS technically falls under the umbrella term EAI. iPaaS brings a multi-tenant cloud runtime, subscription pricing, pre-built SaaS connectors and low-code flow designers, thereby reducing setup effort, server operations and time-to-value compared with classic ESB projects of the 2000s. In larger organisations, both models are often operated in parallel, for example an existing on-premises platform for internal core systems and iPaaS for connecting new cloud applications.
Why choose EAI instead of direct point-to-point connections?
If n systems are each connected directly to one another, up to n×(n−1)/2 interfaces arise, meaning that with ten applications, up to 45 individual connections would already have to be maintained. This so-called spaghetti integration becomes harder to maintain with every additional system, because each interface has to be developed, tested and updated individually whenever something changes. EAI breaks this pattern with a central hub: each system communicates only with the integration layer, reducing the number of connections to one per system and making the coupling loose instead of tight. The trade-off is that the central layer becomes a potential single point of failure and must therefore be designed for high availability and monitored accordingly.
Is an enterprise service bus (ESB) still relevant today?
For greenfield projects, a classic ESB is rarely chosen anymore, as most new implementations rely on iPaaS, API-led integration or an event streaming platform such as Apache Kafka. Existing ESB installations, however, continue to run in many DACH companies and are being migrated step by step, because an ESB as a middleware type still provides routing, transformation, orchestration and monitoring centrally. Microsoft BizTalk Server 2020 is the final product version and remains in mainstream support until April 2028 (extended support until April 2030), while SAP Process Integration/Orchestration (PI/PO) leaves standard maintenance at the end of 2027 and is being replaced by the cloud-based SAP Integration Suite. A complete replacement takes several years in practice, as hundreds of integration flows often have to be migrated and retested.
Which EAI patterns should ERP decision-makers know?
Four integration patterns cover most of what happens in practice: message queue for decoupled asynchronous handover (an order lands in a queue and the ERP consumes it), publish/subscribe for distributing events to several recipients simultaneously (a master data change goes to CRM and web shop in parallel), request/reply for synchronous queries such as an availability check, and orchestration for multi-step business processes spanning several systems. The standard reference work is “Enterprise Integration Patterns” by Gregor Hohpe and Bobby Woolf from 2003, which describes 65 patterns in a pattern language. These patterns can still be found today as building blocks in modern iPaaS and streaming platforms, which is why they provide a good common language between business departments and IT regardless of the specific product.
Which EAI/iPaaS providers are established in the DACH mid-market?
In the classic EAI segment with on-premises roots, you will find providers such as SEEBURGER (Bretten), Lobster_data (Pöcking), X4 BPMS from SoftProject (Ettlingen), IBM App Connect and the webMethods platform (which moved from Software AG to IBM in mid-2024). In the cloud iPaaS segment, Boomi (formerly Dell Boomi), MuleSoft (Salesforce), the SAP Integration Suite, Microsoft's Azure integration services (Logic Apps, Power Automate), Workato and Celigo are widely used, and in the EDI-focused area additionally ecosio (Vienna). In practice, the decisive selection criteria are less the brand name than the availability of suitable ERP connectors, an EU data centre, German-language support and established DACH implementation partners. Since the provider market is continuously consolidating, an up-to-date market comparison based on your own system landscape is recommended before making a decision.
When does open-source EAI (Apache Camel, n8n) make sense instead of commercial iPaaS?
Open-source integration is viable if an internal platform team with sufficient operational maturity is available, as Apache Camel has been in productive enterprise use for over 15 years (first release in 2007) and n8n is well suited to low-code flows. The central trade-off is lower licence costs versus greater operational responsibility, because monitoring, patching, scaling, service levels and 24/7 on-call duty rest entirely with your own team. Mid-sized companies without a dedicated integration team therefore usually choose commercial iPaaS platforms, above all because of contractually guaranteed support SLAs and ready-made connectors. A sound decision derives less from the licence price alone than from the total cost of ownership over several years, which must factor in personnel, operations and downtime risk.