My background is medical devices (21CFR), not aerospace. The "story" I like to tell about how much procedures matter is the stack of $1,200 single board computers I was offered because when they arrived on the loading dock, the person from Receiving didn't follow the proper procedure, so they couldn't be sent to Manufacturing to be assembled into the $700,000 instrument we sold but were instead heading for the dumpster.

$12,000 in perfectly working hardware that had to be scrapped because someone didn't fill out the proper paperwork. Luckily, we (software dev) intercepted them and found other uses for them.