All buildings - including stations should have maintenance schedules. There are things to do hourly (or when open), every 2 hours, 4 hours, daily, weekly, monthly, and yearly. In addition you have 5, 10, and 30 year remodel cycles.
Of course you always have someone do urgent maintenance - if a pipe breaks you fix it now. However replacing that pipe might leave a poorly patched wall until the next 10 year cycle when the fix is made invisible.
You have to empty trash, clean the floors, and other similar things several times per day.
Every year you replace filters and do a deep cleaning. (check the documentation for equipment - sometimes this might be a 1 month cycle not 1 year!) You also do a full inspection of everything, touch up paint, and patch anything else. This should be very routine, and thus always cost the same (inflation adjusted).
Every 5 years you repaint. You also replace carpet where overly stained. That is touch up the cosmetics in a more in depth way. However this is a small cost.
Every 10 years you have to do significant work in the bathrooms (While toilets can last for centuries they start to look bad when you try in a commercial setting). If there is a kitchen it also needs significant work. Avoid moving major things, but this is a higher cost. You should probably be replacing benches on this schedule.
Every 30 years you do a major remodel. Here is where you update everything at sometimes high cost. Add elevators if you don't have them. Expand the station footprint if it is too small (you need more stains). Move where the doors are. Change the station approaches. Add more bathrooms. This will be expensive.
Of course you always have someone do urgent maintenance - if a pipe breaks you fix it now. However replacing that pipe might leave a poorly patched wall until the next 10 year cycle when the fix is made invisible.
You have to empty trash, clean the floors, and other similar things several times per day.
Every year you replace filters and do a deep cleaning. (check the documentation for equipment - sometimes this might be a 1 month cycle not 1 year!) You also do a full inspection of everything, touch up paint, and patch anything else. This should be very routine, and thus always cost the same (inflation adjusted).
Every 5 years you repaint. You also replace carpet where overly stained. That is touch up the cosmetics in a more in depth way. However this is a small cost.
Every 10 years you have to do significant work in the bathrooms (While toilets can last for centuries they start to look bad when you try in a commercial setting). If there is a kitchen it also needs significant work. Avoid moving major things, but this is a higher cost. You should probably be replacing benches on this schedule.
Every 30 years you do a major remodel. Here is where you update everything at sometimes high cost. Add elevators if you don't have them. Expand the station footprint if it is too small (you need more stains). Move where the doors are. Change the station approaches. Add more bathrooms. This will be expensive.