In California, and many other states, other than cooking for direct sale, you have to commissary the food. So, for a food such as BBQ, that takes a long time to cook, and then is held on the truck at safe serving temperatures, you are cooking it off-site. Many will cook through the night, then fire up the smoker and reheat on it, as that still gets the smoke rolling, minus the having to be there cooking on site.
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."