Dead on Arrival (DoA)

an event / a problem
a network event (ネットワーク障害)

Service outage
Network outage
Power outage

troubleshoot to isolate the problem

Problem not found (PNF) / Non-reproducible

Customer found defect (CFD)

bug (ソフトウェアのみ)
defect / problem

defective part / defective component

Field Replaceable Unit (FRU)

FCO (Field Change Order) 回収指示。市場に出た製品を回収して交換
RCO (Return Change Order) 交換指示。他の修理のついでに交換
ECO (Engineering Change Order) 技術変更指示。機能変更。

visual inspection

It's a feature.