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

Engineers are continuing to investigate the issue in order to identify the underlying cause of the problem.

Problem not found (PNF)
No Trouble Found　(NTF)
Non-reproducible
Could Not Duplicate (CND) ログには残っているが再現しない

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.