Software systems are very much like Rube Goldberg machines. End user inputs some data here, and it should go through 3 other systems and an email should pop out the other end.
Unfortunately, visibility isn't always built-in to these systems, so troubleshooting them is like trying to diagnose why the nut didn't slide down the unbent paperclip in the dark.
see also
DarkIsTheDefaulttags:
ComputersAndTechnology