Grind in the last area (Dark and Machine type digimon). They're higher leveled, and give more experience than area 1. And you can't unlock Process Factory in Dawn. It's a Dusk exclusive area. You're probably thinking of Shadow Abyss. The farm quests that unlock it are the Lazy Megidramon and Cool Vikemon farm quests.
It would appear that I have been driven to madness. Probably would have been faster to walk.