Making something (hardware or software) more reliable along a certain axis. (More heat-tolerant, more able to withstand vandalism, able to go a longer period without ScheduledMaintenance?, etc.) This is a GoodThing up to a point, but becomes an AntiPattern when the plating makes the product more expensive than the worst damage it could likely cause.
I keep on adding ArmorPlating to reduce the number of support calls requiring engineering intervention.