For example, what if you have 100 valves in a process plant. You want to show at a glance their status, with the most important thing to notice is a value that indicates a valve that is in critical condition.
I've implemented something along these lines - here the 'plant' is split into sections and then you display the sections in a hierarchical order and display a count of the red / green from each section along with a histogram:
A sorted list, with the important values on top. To add even more information for "quick-scanning", you can include the use of color coding (red colors for items at the top of the list, green for those at the bottom for example). While you could also use icons, just adding color coding keeps your interface simpler.
The sorted list assumes that it is not important for the user to quickly search for a specific item, because then you may have to consider keeping the valves in a fixed order (users expecting values of a certain valve to be on the lower-right corner, for example).
Make the status distinguishable – use color coding, icons, different styles
Make the data organized – sorting, filtring to minimize cognitive efforts
Be sure of correct user mental model – to recognize status values