Creating Object Models/Class Diagrams in Visio 2016
Visio 2016 does not provide full support for creating object models/class diagrams. In fact, its support is rather meager, and much of the richness needed to depict realistic object models and class diagrams is simply missing. In addition, many of the defaults make for rather poor-looking diagrams. This page lists some of the ways to improve object models, to facilitate readability and compatibility with standard notation and conventions.
Resizing classes/objects
As a default, Visio 2016 has the dimensions of classes/objects locked. In prior versions, you could resize through changing font styles and sizes. This workaround does not work in Visio 2016. However, you can resize by right-clicking the class in the ClassName area. This should generate a couple of popups, plus highlight the 8 anchor points for the object. Grab the yellow dot on the right-middle, and you should be able to resize horizontally. Vertical resizing is automatic, based on horizontal wrap-around.
Including multiplicities on the associations
After you have added and named the association, right-click on the association line. This should generate two popups. One option on the text popup should be Show Multiplicity, which you can toggle on. This will add four multiplicities to the association – M1, M2, M3, and M4. I’d recommend using M1 and M3, and deleting M2 and M4. Double-clicking on the multiplicity lets you add the appropriate text here.
Including association classes
There doesn’t appear to be a good solution for this one. A possible workaround, albeit rather ineffective, is to add a class for the association class, and draw a line to the appropriate association. Keep in mind that this will not anchor it to an appropriate glue-point, and any repositioning of the parent classes would cause some headache on this score.