Alarms were originally shown on Piping and Instrumentation Diagrams / Drawings (P&IDs) to document hardware requirements for installation in a (panelboard) control room. This was important because there was limited real estate in the control room for the alarms (displayed on Panalarms and light boxes) and there was a real cost to wire them up (approximately $1000 / alarm). Alarms are often treated as if they are “free” in the modern distributed control system (DCS). They are configured in software and displayed on a PC monitor (HMI). This raises the question whether it is still necessary, or even beneficial, to document DCS alarms on P&IDs.