You can use a flowchart like this to show the exact place in the process of ringing a doorbell where a nonfunctional doorbell might be failing.
Text in this example:
Doorbell failed to ring Bell-solenoid unit
fails to ring Low voltage from
battery Switch fails to
make contact Contacts broken High contact resistance Clapper not attached Solenoid link broken Clapper stuck Clapper broken Positive pole broken No electrolyte