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.
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.
Simon is an independent software development consultant specialising in software architecture and the author of Software Architecture for Developers. Simon lives in Jersey and regularly speaks to audiences around the world. You can find Simon on Twitter at @simonbrown and Google+.