Nine year ago in Ireland, a railway viaduct over Malahide Estuary collapsed. Thankfully, no one was hurt, but it was a close run thing. On evening of August 21, 2009 as a train was crossing the viaduct, the train driver noticed that something had fallen off the bridge. After crossing and setting up a warning to prevent other trains from crossing the viaduct, the train driver walked back along the track. He discovered to his horror that the bridge he had just passed over had collapsed. The foundations of one of the pillars supporting the viaduct had been scoured away.
As is often usual with human error, there were multiple mistakes and missed opportunities that lead to a rush hour train going over a (very) unsafe viaduct. For example - the foundations of viaduct were susceptible to scour and (even worse) former employees of the rail company knew this. An excellent article by Sean Brady in Engineers Journal sets this out well:
The IP angle is close to the end - 'By 2009, it appears that the knowledge and information relating to the scour susceptibility of the Malahide Viaduct resided in the heads of a number of individuals who had left the division, rather than in a formal system that was accessible to the engineers responsible for the structure.'
Which finally brings us to the lesson in all of this - if you don't have a formal system for collecting the useful stuff in the heads of your staff (otherwise known as intellectual property or IP), each nugget of IP generated by an individual will leave in their head when they leave your firm - aside from your firm leaking value, it can also cause catastrophic failures. If you do have a formal system for collecting your staff's IP, it stays with your firm. We can even help you file patents for the good stuff...