PlantUML and Structurizr

Create models not diagrams

Despite the seemingly high unpopularity of UML these days, it continues to surprise me how many software teams tell me that they use PlantUML. If you've not seen it, PlantUML is basically a tool that allows you to create UML diagrams using text. While the use of text is very developer friendly, PlantUML isn't a modelling tool. By this I mean you're not creating a single consistent model of a software system and creating different UML diagrams (views) based upon that model. Instead, you're simply creating a single UML diagram at a time, which means that you need to take responsibility for the consistent naming of elements across diagrams.

Some teams I've worked with have solved this problem by writing small applications that generate the PlantUML diagram definitions based upon a model of their software systems, but these tend to be bespoke solutions that are never shared outside of the team that created them. Something I've done recently is create a PlantUML exporter for Structurizr. Using PlantUML in conjunction with the Structurizr open source library allows you to create a model of your software system and have the resulting PlantUML diagrams be consistent with that model. If you use the Structurizr's component finder, which uses reflection to identify components in your codebase, you can create component level UML diagrams automatically.

A PlantUML component diagram

Even if you're not interested in using my Structurizr software as a service, I would encourage you to at least use the open source library to create a model of your software system, extracting components from your code where possible. Once you have a model, you can visualise that model in a number of different ways.

About the author

Simon is an independent consultant specializing in software architecture, and the author of Software Architecture for Developers (a developer-friendly guide to software architecture, technical leadership and the balance with agility). He’s also the creator of the C4 software architecture model and the founder of Structurizr, which is a collection of open source and commercial tooling to help software teams visualise, document and explore their software architecture.

You can find Simon on Twitter at @simonbrown ... see for information about his speaking schedule, videos from past conferences and software architecture training.

Re: PlantUML and Structurizr

Nice article. Structurizr look great. PlantUML is wonderful in my opinion, and I really enjoy hearing about projects that utilize it. I don't understand why people are not writing UML as much these days, but it is very useful for me. We use NPlant for generating component and class diagrams from C#. A picture is worth a thousand words. Take a look at my project called when you have a minute. It is a web-based PlantUML editor. I would love to add projects like this for converting both ways from plantuml-to-code and also code-to-plantuml. Perhaps your project could help with that for Java?

Add a comment Send a TrackBack