Systems Integration

Interoperability Perspectives

Prof. Dr. Christian Drumm

2026-10-09

Interoperability Perspectives

A broad topic that can be analyzed from multiple angles

  • Integration styles
  • Levels and tasks
  • Integration scenarios and methods
  • Interoperability concerns

These perspectives form the foundation for the rest of the course — we will return to them regularly.

Integration Styles

Four basic integration styles (Hohpe & Woolf, EIP Chapter 2)

  • File transfer
    • Applications produce or consume files to share data
  • Shared database
    • Multiple applications share data in a common database
  • Remote procedure invocation
    • Applications expose functionality to receive data or trigger processes
  • Messaging
    • Applications exchange messages via a messaging system

Exercise: Analyse Integration Styles

Task

Aspects to Explore

  1. Definition — what is this style, how does it work?
  2. Key characteristics — synchronous vs. asynchronous, data centralization, coupling, …
  3. Pros & cons — scalability, performance, reliability
  4. Relation to integration levels — syntactic, semantic, organizational
  5. Relation to integration scenarios & methods
  6. Scenario application — is the style effective for synchronizing stock information between an ERP system and a web shop?

Prepare 1–2 slides summarizing your key findings. You have 30 minutes.

Levels and Tasks

Levels

  • Syntactic — the data format
  • Semantic — the meaning of the data
  • Organizational — interoperability across organization borders

Tasks

  • Exchange — exchange of data between services and applications
  • Integrate — integration of multiple services and applications
  • Orchestrate — coordination of services and applications across system boundaries

Syntax vs. Semantics: Consider the simple XML tag <customer>. While the data format may be identical, the meaning of Customer in a banking application is quite different from the meaning of Customer in a health insurance application.

Levels and Tasks

Examples of technologies and concepts used on different levels

Level / Task Syntactic Semantic Organizational
Exchange Exchange formats: CSV, EDIFACT, XML, JSON
Query languages: SQL, XPath		 Schema mapping, ontologies Message exchange
Integrate Databases, REST, OData Schema languages, generic and user-defined schemas. Correlation and choreography
Orchestrate BPMN, Petri Nets, Workflow engines Verification, service invocation, integration patterns Choreography

Integration Scenarios and Methods

Different integration scenarios and methods are used in different domains

Application Domain UI Integration Process Integration Application & Function Integration Data & Information Integration
Method / Style UI-oriented Message-oriented Message-oriented Query-based
Realization Portals, Robotic Process Automation, Workflow management systems Process engines EAI systems, Message-oriented middleware, ETL tools ETL tools, everything mentioned in Levels and Tasks

Interoperability Concerns

Three levels, two questions

  • To execute processes across heterogeneous systems, interoperability must be established on three levels:
    • Data level
    • Service level
    • Process level
  • On each level, two questions need to be answered:
    • What is to be exchanged?
    • How is it exchanged?

Interoperability Concerns

Data level

  • What: exchange formats (XML, JSON)
  • How: protocols (REST, OData)

Process level

  • What: still concerned with exchange formats and protocols
  • How: process orchestration and choreographies e.g. using process engines or EAI systems

The same what / how pattern applies on all three levels (data, service, process).

Summary

  • Interoperability is a broad and complex topic — it spans multiple levels of system interaction, from data exchange to process orchestration across organizations
  • The four perspectives — integration styles, levels and tasks, scenarios and methods, and concerns — will form the foundation for the rest of the course
  • We will apply them to analyse case studies and implement them in the lab exercises

References

  • S. Rinderle-Ma, J. Mangler, and D. Ritter, Fundamentals of Information Systems Interoperability: Data, Services, and Processes. Cham: Springer International Publishing, 2024.
  • G. Hohpe and B. Woolf, Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions. Boston Munich: Addison-Wesley, 2013.