Level of abstraction - on which level we will simulate economy? I have at least two of them: 

- Individuals based 

- Buildings/Places based

 - First one will simulate interaction between diferent individuals like miners, woodcutters, blacksmithes, traders, citizens and so on. Thay will have some needs, will buy some items/resources

 - Second, based on building/resource deposits. Like ore comes from mines, than to forge, smelts into metal which will be used in forge to produce items  which will be used in military buildings, and so on.

  Hm as writing it understang that second variant is not good enought, so maybe later we can combine tham together and add buildings, and resource deposits into simulation too.

But for first lets start from first metho, and asume that individuals prodeces goods by tham self.

Starting with this individuals:

- Miners - produce ore and coal, needs tools, food, and Gears/clothes

- Woodcutters - produce raw wood, need tools, food and Gears/clothes

- Smelters - produce metals, needs in coal, food, ore, clothes, tools

- Blacksmithes - produce metal items/tools, needs in metal, coal/fuel, food, clothes, tools

- Farmers - produce food, linen, cotton, wool, needs in tools, clothes, maybe seeds and fertilizers(Animal manure, with it we can implement farming productivity levels)

- Tailors(abstration for all clothes production) - produce clothes, consume food, raw cotton,linen, wool.

- Carpenters(abstract for all wood works) - consume wood,  food, tools, produce wooden tools, wooden weapons.

- Citizens - (abstract for diferent individuals, which dont have production skills.Military, gov, nobbles, and so on.), consume food, and all kind of ready items like weapon, tools, decor, and so on, their need depends on later-added characters profile, with interests, needs, and so on(like need in safety, food, house, luxury stuf)

Later we will add a more consumers and produces, but for start it is enought i`m think.