Sometimes software has usability bugs, and you can tell that it ought to be easier to install / maintain / perform a task in it. However, not all software is a one-click smartphone app with simple sliders, for example Apache HTTP Server or Microsoft IIS.
Is there a scale that can help you identify how difficult a task your software solves, and therefore identify which modules are inherently complex rather than usability-poor, and where you have a usability issue that is getting in the way of a complex task?