I work for a company with around 50k machines globally... one time we discovered a machine that was supposed to have been decommissioned five years prior still

I work for a company with around 50k machines globally... one time we discovered a machine that was supposed to have been decommissioned five years prior still sitting on the network, just waiting to do its job. We ended up scanning our entire IP space and finding 10-20 other machines in the same state. We now have a process that routinely scans our entire IP space for machines that somehow get lost from our inventory system.