Scavenging
This is an action that you can take alone or with Followers in any map area, and it is also a Job that you can assign followers to do on their own.
If doing it yourself with or without Followers, each Scavenge attempt will take an hour (take the Investigate Area -> Scavenge Area action), and will succeed or fail depending on your own Survival skill. You will have a reduced chance to find something in Safe areas, whereas in Wild areas there is a chance you'll attract an attack from a rival scavenger gang (which is the main reason it's worth having your Followers accompany you on Scavenge actions). If your scavenge attempt is successful, there's a small chance that you'll find something unusual (e.g. a shotgun; maybe "finding" things like this is why you get attacked sometimes?)
If assigning personnel to the Scavenger job, they will do this 9am-5pm; it is theoretically risky, though in practice so far has turned out to be safe; and they will bring back a guaranteed haul unlike a Scavenge action, and their haul will be greater - but that's because a Scavenge action takes only for an hour. They will bring back less if their Survival skill is 20 or lower, and more if it's 60+. They will also bring back extra if they are smart (Intelligence 60+), like you (Affection 60+), Ikaanos is thriving (Prosperity 75+), or if they have the Scavenger trait. This Trait also means they will have a chance to bring back things other than just standard "merchandise" (Durasteel, tendstims, energy cells); otherwise this chance is zero.