Typically it means making multiple passes at the data.The real killer is that the algorithm or rules quickly become obsolete as new information is available.

As part of its effort to streamline and terminate obsolete programs, HUD is considering eliminating GEM and removing its regulations.

Until recently, these loans were deemed obsolete - but they have made a comeback.

I do realize sources become obsolete, but your two years guideline makes a lot of sense in hindsight.

If you’re familiar with SF apts it’s a prime example of what happens when you get rent control - crappy buildings/obsolete units and insane market rents that are artificially inflated by rent control.The thing to watch out for if you own commercial deals (5+ unit apts too), is on the 2020 ballot they’re going to have a vote to separate prop 13 so commercial deals are no longer protected.

I haven't had guests complain about it but I freaking hate VRBO's website, I think it's obsolete and every process is more complicated than it needs to be.  

Older car washes are becoming obsolete.   

I would say that in properties with obsolete technology (thinking knob & tube electrical) it can be very hard to make even incremental improvements without replacing the whole system.

They have not been maintained or have just become obsolete. 

We buy obsolete single-family houses, fix them up, and rent them out.