Factories and logistics

Special factories make products from materials. They buy materials automatically by truck from nearby factories, farmland, and ports.

Food: wheat (farmland) → flour mill (flour) → food factory (food) → shops
Iron: iron ore (port) → steelworks (steel) → car factory and railcar factory
Chemicals: crude oil (port) → petrochemical plant (chemicals) → electronics factory

When you build a factory, it is set to “Use myself” and starts running right away.
For farmland and ports, choose the “Product” on the building sheet (wheat for farmland; iron ore or crude oil for ports).
Every hour, it buys materials and makes products.

How much it makes in a day depends on floor space.
Materials cost the market price + shipping. When importing is cheaper, or when there isn't enough, it imports (you can also choose “Don't import”).
Stock beyond 6 hours' worth is sold on the market. Food is sold to nearby shops.
There are also costs such as electricity and labor. If anything is unpaid, making and buying stop.
You can see stock, 24-hour sales and costs, and market prices in “≡” → “🏭 Facilities & factories”.
If you ship with your own trucks ordered at a bus depot, there is no shipping cost.