Deep Space Settlement is a 4X real-time strategy game focused on empire building and grand-scale space battle.
Another factory, this one producing electronic components. E.C's together with casted pieces produce all kinds of "higher tier" resources, like actual functional parts. A turret for instance needs both casted pieces and electronic components. A station, like the E.C factory itself, needs tools, hullplating, E.C.s, casted pieces and workers to be build.
To build a basic corvette you'd need tools, hullplating, E.C.s, casted pieces, SSPs(standard ship parts) and workers.
So essentially, there's tools, hullplating and workers which you need to build units and stations. But those would just be empty shells, so you have E.C.s and casted pieces to build the parts that make the stations and units work like reactors, shields, weapons, sensors, etc.