Imagine a team working on a complex project where each member uses different, incompatible tools. Without a common platform, confusion arises, communication breaks down, and the project falters. In enterprise architecture, miscommunication can lead to similar issues — delays and failure to achieve strategic objectives. Models serve as our common language, providing clarity, structure, and a shared understanding of complex systems.

Let’s introduce some concepts used in this article.

Concepts

Model: An abstract representation of a system or process. Think of it as a visual, showing you the essential features without overwhelming you with the unnecessary—for example, a diagram showing the integration of enterprise systems within an organization.

Shared Mental Models: The common understanding that a group of people holds regarding how a system, task, or process works.

Architecture Method: The structured approach to developing architecture. This includes applying models to visualize and organize systems at different levels.

Architecture Framework: A set of guidelines that provides a foundation for creating architecture. Frameworks offer a structure to plan, develop, implement, govern, and sustain architecture.

Notation: A system of symbols or characters used to represent visual elements of a model.

Design & Engineering Methodology for Organizations (DEMO) is an enterprise engineering method focused on understanding and modeling organizations as coherent systems. Using a rigorously defined methodology, it bridges the gap between business, organization, and IT.

ArchiMate: A specification for modeling enterprise architecture.

Business Process Model and Notation (BPMN): A graphical representation for specifying business processes.

Case Management Model and Notation (CMMN): A graphical representation for expressing a Case graphically and an interchange format for exchanging Case models among different tools.

Decision Model and Notation (DMN): A standard for modeling and automating decisions within an organization’s business processes.

Unified Modeling Language (UML): A standardized visual language used to model software systems.

Systems Modeling Language (SysML): A general-purpose modeling language designed to model complex systems, particularly in systems engineering. It extends UML.

Return on modeling effort (RoME): A concept that evaluates the benefits gained from the effort invested in creating and refining models.

The Importance of Models in Architecture

While chaos can drive adaptability and resilience, clear communication is essential to harness its benefits. In architecture, models serve as simplified representations of (perceived) reality or a preferred future, providing a structured way to describe complex systems. Though no model can perfectly capture the real world, its communication value makes it powerful.

Modern architects use various models as a shared language that connects diverse stakeholders — from engineers and designers to product owners and business leaders — ensuring alignment across domains. Whether aligning business strategy with IT implementation or integrating software architecture with system engineering, models offer a common understanding that enables effective collaboration.

Architecture models help build and maintain shared mental models among stakeholders, establishing common ground and mutual understanding. Models ensure that when stakeholders discuss a system or process, everyone is literally and figuratively on the same page.

Different Ways to Model Architecture

There’s no one-size-fits-all when it comes to modeling. Different problems require different models, methods, and frameworks. Below is an abstract list of different ways to model tailored to specific focus areas. However, this is by no means an exhaustive list. If you’ve used other notations or techniques to model architecture, feel free to share them and contribute to this article:

Enterprise Architecture and ArchiMate: ArchiMate is a widely used specification designed to represent the entire enterprise’s architecture. It provides a standardized “language” for modeling strategy, business architecture, information systems, technology, and implementation & migration while maintaining a high-level view of how these layers and their respective elements interact. ArchiMate is valuable for framing stakeholder concerns using the viewpoint mechanism.

Enterprise Engineering and DEMO: The DEMO methodology is centered around designing organizations as coherent systems. DEMO is unique in its focus on the essence of the organization, looking at how transactions are conducted and fulfilled between actors. It’s a powerful tool for modeling human and organizational processes, especially where complex interactions between roles and responsibilities need to be understood.

Business Process, Case Management, Decision Management, and BPM+: BPMN, created by the Object Management Group (OMG), models the flow of business processes. It allows architects or analysts to represent how tasks are executed across different departments, making it an excellent tool for improving business workflows. BPMN is beneficial when examining process optimization, bottlenecks, and opportunities for automation. The OMG links the BPMN, CMMN, and DMN standards together as BPM+. OMG states, "While the standards can be used separately, they can be used to expedite long and ambiguous organizational processes to improve quality and consistency.”

Software Architecture and UML: UML is a well-known software architecture and engineering specification. It’s widely used to model software systems, breaking complex structures into clear and understandable components. UML provides diagrams representing anything from system components to data flows, offering flexibility in describing and communicating software architectures. It also provides a use case diagram that can be used to reason about use cases.

Systems Architecture and SysML: SysML extends UML for systems engineering. It’s designed for more detailed modeling of complex systems, particularly in aerospace or automotive industries where both software and physical systems need to be understood and integrated.

In enterprise data modeling, various techniques/models, such as the entity-relationship model, are used by data architects and engineers to create a graphical model of an enterprise's data.

Each specification/technique offers a distinct way to visualize and reason about architecture. The choice of model depends on the type of system, the audience, and the level of abstraction required by stakeholders.

When to Model

Architects communicate with models, and we tend to be keen on modeling. But not everything needs to be modeled.

Significant effort can be invested in refining a model to “predict” reality perfectly. However, this pursuit of perfection comes at a cost, as architects and architecture teams must dedicate resources to enhancing the model.

“All models are wrong, but some are useful,” said the famous statistician George E.P. Box, which also applies to modeling architecture. Models aren’t about capturing every detail or striving for perfection but focus on key elements to foster understanding, aid problem-solving, and improve decision-making.

So, when should you model?

The simple answer is whenever your stakeholder communication demands.

Architects, as masters of complexity, use models to abstract and simplify. These models allow stakeholders to share a vision, align strategies, and make informed decisions. Whether you’re using ArchiMate to model the enterprise, DEMO for enterprise engineering, or UML to represent software systems, the goal is to create clarity from ambiguity.

Modeling offers numerous benefits across different fields (not just architecture), including enhanced understanding, “prediction,” and problem-solving. But remember, modeling isn’t about perfection — far from it. It’s about creating valuable representations that guide stakeholders. Sometimes, the simplest model can be the most powerful.

Further Reading

• Enterprise Engineering — The Enterprise Engineering Institute

• Enterprise Modeling with DEMO — The DEMO Methodology, Chapter 12 from the book Enterprise Ontology by Jan L.G. Dietz & Hans B.F. Mulder

• ArchiMate® 3.2 Specification — The Open Group online publication

• UML — Object Management Group UML specification

• BPM+ — Object Management Group BPM+ specification

• SysML — Object Management Group SysML specification

• RoME — Return on modeling effort, Chapter 4 of Enterprise Architecture — Creating Value by Informed Governance by Martin Op’t Land, Erik Proper, Maarten Waage, Jeroen Cloo, & Claudia Steghuis

• Research Study: What Do I Get from Modeling? An Empirical Study on Using Structural Conceptual Models (Open access) by Isadora Valle Sousa, Tiago Prince Sales, Eduardo Guerra, Luiz Olavo Bonino da Silva Santos, and Giancarlo Guizzardi