I believe that the DMS is produced during the boil. The steam lifts and removes the DMS, so it is removed as fast as it is created.
The lightly kilned malts, like pilsner malt, contain a lot of the precursors that become DMS when over about 170F. So, if you don't boil, you won't get any DMS. And when you do boil a wort from pilsner malt, it's a really good idea to chill quickly and don't let your wort sit between 170 and 212 for long.
This is all from my bad memory, and mostly just regurgitated from stuff I heard and read, so you know just treat it like the rest of the garbage on the webz.
(btw, I've made several BW with 15 minute boils and never any DMS)