An important production line goes down several times a week. Bob seems to have the “magic touch” and is the only maintenance technician who gets it running again in only minutes. Everyone else takes over an hour, running diagnostics, reseating control cards, and basically going through every step of the manufacturer’s published trouble-shooting guide.
Fortunately, these production stoppages happen mostly on Bob’s shift. When Bob isn’t on vacation or isn’t away at training or isn’t tied up on another repair, he can quickly get the thing humming again. And he always states a different reason.
What’s going on?
This quiz is from an actual case. The control system has an interlock/permissive that stops the machine if the cabinet door switch opens. For safety, a manual reset is required to restart.
One operator opened (then closed) the door when he wanted an extra break. Bob caught the operator doing this, and saw an opportunity for both of them. He told the operator to hip-bump the door hard, to avoid detection. Bob would pretend to quickly fix some other cause.
Bob’s scheme gained him the hero reputation he expected. But this situation drew suspicion, and then investigation. After both men were fired, the door was padlocked and a contact bounce delay was added.
