When a fire breaks out, we call the Fire Department. They dispatch a highly trained, coordinated response team. Each team member knows what he will do without a boss onsite to figure out who should do what.
We talk about “putting out fires” when equipment goes down. Do you dispatch a repair response team or just send available techs?
Often, the latter is OK. For example, the sump pit high level alarm has tripped. You don’t need a response team for that; a qualified repair technician can handle any of the likely failure modes or repair strategies.
However, what if a robotic welder goes down? The cause might be any of a dozen things (e.g., PLC, motor overloads, etc.) or combination thereof. This equipment needs an existing response team (that has trained as a team), with a person dedicated to each major area of expertise. While Joe’s doing PLC diagnostics, Barb is checking the MCC and so on. Nobody has to take time to figure out who does what because they already know their roles.