Your data center uses a diesel generator as backup for two different power grids provided by your regional power company. During a period of unprecedented heat, you experience brown-outs on both grids simultaneously. The diesel generator starts up but only runs for two minutes before it also shuts down, leaving your entire data center down until grid power can be restored. Further inspection reveals a clogged fuel filter.

Failing to schedule preventive service for the backup generator is a failure in which function?