Investigating dependencies

When developing or maintaining Caché Objects applications, or even ones written in plain COS code, it's sometimes useful to investigate dependencies. Yuzinji is a tool that analyzes the Caché class dictionary plus the COS code within methods and routines, then feeds its results into Structure101g Studio.

By doing this it becomes easy to ask questions such as "Who uses this piece of code?", getting the information in a format that is easy to explore further. For example, I recently analyzed all the packages in the SAMPLES namespace of the 2016.2 Field Test and was interested to observe a dependency on the %apiOBJ routine. Here's a screenshot of what this toolset showed me:

Two classes contain methods that invoke a couple of entrypoints in %apiOBJ, specifically DecomposeStatus^%apiOBJ and DisplayError^%apiOBJ. A cleanup effort might replace these with calls to classmethods of %SYSTEM.Status, i.e. $System.Status.DecomposeStatus and $System.Status.DisplayError.

Do you have any favourite tips, tools and techniques to share in this area?