This page gives you an overview over the status of the hardware of all your customers, aggregated by hardware type.
The O/I/O/R (Online, Issues, Offline, Ready) column tells you the number of units with each of the 4 main statuses:
The unit is mining properly without problems
The unit has one or more problems (not all hashing boards online, temperature above threshold, hash rate below threshold)
The unit has been initially recorded into the database but has yet to go online for the first time. These units are not being listed in the units view per default. You can choose to do so by unchecking the box ‘Exclude units marked as “ready”’ above the units list.