In this article, we focus on the combination of two methodologies: the C4 Model and Event Modeling. These approaches have proven particularly effective in the context of large or international companies dealing with distributed systems or transitioning from monolithic applications to a cloud-native approach.
From my extensive experience in large corporations, I’ve observed that the key to success lies in the appropriate choice of methodology for capturing the architecture of systems. This choice is crucial for efficiency, sustainability, and readability of documentation, which must be understandable to various roles involved in the software product’s lifecycle.
Readability as the Holy Grail of Diagrams
From my perspective, the readability and understandability of a diagram are its most important aspects. A diagram that is comprehensible to a wider audience is more likely to be kept up-to-date and becomes a more valuable source of information. If a diagram is complex and difficult to understand, it loses its purpose.
The Combination of C4 Model and Event Modeling
The C4 Model employs a hierarchical approach that is intuitive and easy to understand, similar to maps. Event Modeling, on the other hand, provides a clear chronological sequence that is easy to follow. Both approaches use a limited set of diagrammatic elements, simplifying understanding and eliminating the need to navigate complex elements, as is sometimes the case with BPMN diagrams.
Both methodologies also focus on specific contexts, unlike some other methodologies like ArchiMate, which can sometimes be too general, making it difficult for readers to grasp the correct context immediately. The advantage of both approaches is that they do not require any special elements or language definitions, so they can be used in various diagramming tools from EA to Draw.io, Miro, or any other diagram creation tool.
Each role requires something slightly different from a diagram. From a solution architect’s perspective, you might be more interested in an abstract view of system collaboration over time, which Event Modeling provides. Conversely, from a software architect’s perspective, the granularity of components or communication interfaces that the C4 Model provides might be more relevant. For developers, the lower levels of the C4 Model, where details are crucial, as well as the Event Model, to understand the entire use case, can be particularly useful.
We also use Event Modeling for systems not primarily designed as event-driven, to capture the sequence of communication effectively. At the same time, this type of diagram is also readable by more business-oriented colleagues, which is a significant contribution to unifying and understanding use cases.
Conclusion
By combining the C4 Model and Event Modeling, we create a powerful tool for capturing the architecture of distributed systems. This approach enables the creation of documentation that is not only efficient and sustainable but also easily understandable to different roles involved in the software product’s lifecycle.
