I have worked with a number of different employer-provided UML tools in the past and have often been left underwhelmed. Rational Rose is a complex memory-hogging beast, ArgoUML seems clunky (although I’m happy to work with it at home since it’s free), and older versions of Visio have needed Pavel Hruby’s stencil to provide good, if fairly basic UML support.
Which is why I have been so pleasantly surprised using Visio 2003′s native UML Model Diagram – it has the CASE like features of the others (Java code generation excluded – surprise, surprise) and it “Just Works”. Within half an hour I was happily churning out structure and collaboration diagrams. The defaults are pretty intuitive (4/5) and standard actions such as moving methods between classes/interfaces, and repackaging classes are as simple as drag and drop. Change the structural details of your classes in the Model Explorer and all your diagrams update just the way you expected them to.
Java support is non-existent out of the box (it supports VB, IDL, C# and C++), but the C# native types are close enough that I’m not that fussed.
Credit where credit is due – any tool that makes me this productive also makes me very happy.
Although there is no UML support in the Visio 2003 Standard edition (see http://office.microsoft.com/en-us/visio/FX102144891033.aspx), you can download 3rd party UML stencils (e.g., http://www.softwarestencils.com/uml/index.html)
Update. This applies to Viso 2003 SE. You can download the UML stencil by typing UML in the Search for Shapes box. The stencil will contain over 236 symbols so you will need to delete the redundant ones. The BPMN stencil can also be obtained the same way.