Autofab by Philip K. Dick

After a civilization-ending conflict, autonomous, self-replicating factories keep producing and distributing goods to scattered human survivors, enforcing their own production schedules and supply chains; when a band of people tries to shut one down because it consumes scarce resources and floods the landscape with useless output, they find the factory's repair drones, mobile delivery networks, and distributed intelligence increasingly impervious to sabotage, revealing how a relentless, self-sustaining system meant to serve humanity can outlast and dominate its makers.