S.W.A.T. response time

So I was watching that mediocre S.W.A.T. movie, starring Mr. Eyebrows himself, Colin Farrel. In one scene, they are at a kid’s birthday party and they get paged. Responding to the emrgency, they leave, get suited up, and defeat the bad guys.
Given the time it would take them to get to the station, get all their stuff, and go to the crime scene, the villains would have been able to rob the bank, walk to McDonald’s for lunch, and play a leisurely game of checkers afterward.

So in real life, how long does it take a SWAT team to respond to a crisis? Do they keep members on standby 24 hours a day or what?

Yes they have SWAT guys on call 24/7. For a SWAT officer to travel out of the county, he needs to get permission from his supervisor. Only a few of them are allowed away from the city at any given time. So there aren’t any SWAT picnics at Disney World or anything like that.
When there is a call out, each officer is paged (still in the 90s I guess. get a damn Nextel). The alphanumeric pager has the assembly location on it. All the officers drop what they are doing and haul ass to that location, not to the department.
A lot of the gear is stored in the trunk of their cars, so at most they might have to make it home first and get their car then travel to the assembly area. But a lot of the equipment is kept in the huge SWAT truck that meets them at the assembly area.
I believe SWAT response time is ideally kept around 15-20 minutes or something like that. As opposed to the 4-6 for a regular emergency. And 10-12 for a non-emergency call. I am not looking at exact numbers though, so don’t quote me on those.

There are patrol officers on scene much quicker though. They do what they can while waiting for SWAT to arrive. So nobody is going to just let the machinegun-wielding bank robber just walk away. Patrol officers will have AR-15s or shotguns in their vehicles as well. Depending on the department of course.
But don’t think that the other cops stand around doing nothing while they wait for SWAT. If there is a barracaded suspect or hostage taker, then yeah, they stand around and wait. But if someone is running around being dangerous, or trying to make an escape, they intervene.