What is Application Architecture?
Application architecture describes the structure, interrelationships and functionality of the applications within an organisation. It provides insight into which applications exist, what they do, how they interact and how they connect to processes and data flows.
Application architecture is the link between business architecture and technical architecture — it translates business need into software.
🧠 What does an application architecture cover?
| Component | Description |
|---|---|
| Application landscape | Overview of all applications and their functions |
| Interfaces and integrations | How applications communicate with each other (e.g. APIs, messages, ESBs) |
| Application functions | What each application contributes to processes or users |
| User groups | Which departments or roles use which application |
| Lifecycle status | In use, retiring, implementing, replacing |
🏗 Examples of applications in a landscape
| Type of application | Example |
|---|---|
| Case management system | Supports case-based working, e.g. with RGBZ |
| Document management system | Archiving and version control (DMS, RMA) |
| HR and finance systems | Payroll, procurement, reporting |
| SCADA or HMI software | OT applications for process visualisation or control |
| Portals and e-services | Interfaces for citizens, businesses or internal users |
🔁 Relationship to other architecture layers
| Architecture layer | Link with application architecture |
|---|---|
| Business architecture | Determines which functions and processes need to be supported |
| Information architecture | Specifies which data the applications use or produce |
| Technical architecture | Provides the infrastructure on which applications run (servers, networks, cloud) |
A well-designed application architecture prevents duplication, fragmentation and vendor lock-in.
🏛 Use in government architectures
| Architecture | Role of application architecture |
|---|---|
| NORA | References generic functions and principles for service delivery architecture |
| GEMMA | Includes a GEMMA Application Architecture: standard layout for municipal apps |
| WILMA | Applications for water management, monitoring, reporting, asset management |
| MARIJ | Application landscapes within ministries and executive agencies |
🏭 Application architecture in an OT context
In Operational Technology (OT), applications are often embedded or specialised, but they are increasingly part of the broader application landscape:
| OT application | Function |
|---|---|
| SCADA systems | Real-time monitoring and control of industrial processes |
| Historian databases | Storage of time series and process values |
| Asset management software | Insight into maintenance state, calibrations and lifecycle |
| Edge computing platforms | Local data processing on devices or gateways |
| OT–IT integration platforms | Bridge between field equipment and ERP or BI systems |
Application architecture in OT supports management, security, integration and lifecycle management of specialist systems.
🧩 Architecture principles for applications
- Reuse generic functions
- Minimise dependencies
- Use open standards (e.g. REST, JSON, Digikoppeling)
- Avoid duplicate functionality
- Plan lifecycle and maintenance from the outset (Lifecycle Management)
📌 In summary
Application architecture brings structure to the software landscape. It helps organisations — from municipalities and water boards to ministries and industrial sites — manage applications strategically, securely and efficiently.