Orthogonality
This page is inspired by rule three in Geert Bellkeens' blog post 5 rules for better UML diagrams.
A tidy diagram is easier to understand then a messy one. Aligning the elements horizontally and vertically, and using right angled connector lines is a simple step to improve readability.
In the first figure below, the elements have been automatically arranged, with direct connector lines. In the next one, the elements are arranged horizontally and vertically, evenly spaced and with harmonized sizes, and the connector lines are orthogonal. The last diagram is much more tidy and easier to understand.
Messy:
Tidy:
Tools for aligning elements and setting height and with is accessible by selecting one or more elements and right-click. Line styles are set by selecting a line, right-click and select Line Style. The line style in the example above is Tree style - Vertical. This style can be used because all three result classes have the same relationship to DQ_Result: Generalization (subclasses). If one of them had an aggregate relationship, this one would have to be shown with a separate line.