sounds like most of the manufacturing issues I have been involved in...
'why did the machine break?'
'well the spec says to clean it using chemical X but the cabinet with X is 75 feet away and the cabinet with chemical Y is next to the machine so they used Y. They use X and Y interchangeably on other machine so the technicians (note: high-school grads, great guys but not chemists) thought it was interchangeable on this machine.'
'well why aren't they interchangeable on this machine'
'Y reacts with the glue used to assemble the machine, which was a change in the newer versions because of EPA regulations, so doing this weekly maintenance task for 8 years was finally enough to degrade the glue'
'so why was chemical Y stored near here?'
'because X has to be kept so many feet from Y. Last year in the efficiency audit we found techs had to walk to far on average to get X so we moved the X cabinet, which resulted in us moving Y to here.'
'has Y been used on any of the other machines when it shouldn't have been?'
'we don't know and we aren't sure how to check'
Fault trees usually make for really interesting reading.
I'm guessing I can't read the source to this particular fault tree, but I wonder where I might find others. Preferably without digging through e.g. troves of court documents and the like.
Having ongoing and massive issues with a Cisco phone system where I work currently, so I was reading into it as being a Cisco system and not being surprised.
Although agree that Cisco is usually pretty solid.
"Really? That was it? Are you fucking serious?"