Just as the title says; factory planets/stations that specialize in making weapons and missiles (will be unique for each faction) . These planet need new commodities like warheads, ammunition, missile fuel cells(or just fuel cells), ore ingots, and etc.(maybe there can be more but these are ones that I can think of off the top of my head). Also these planets/stations act as major suppliers to military bases. Cut off resources or trade fleets transporting weapons from these factories can cripple fleets and military bases for a faction.
For shipyards it’s a similar concept to the one above but it will use commodities already in game i.e. ore, metal plating, etc. It will have a much, much higher chance for cruisers and capital ships depending on market stability. Wars or Cold War events ramp up production more resources used more ships produced and get a free hull mod with ships purchased. Independents get a junkyard planet where scavengers dump/ sell ships they have recovered. Restores are cost 30% less than normal. Also sell a WIDE variety of of weapons from all factions in your campaign.