Requirements, principles and concepts about optimization for OSH
Open Source Solutions should be designed in a way, other people can understand, build and improve it. The success of the Open Source Hardware evolution adds physical requirements compared to Open Source Software.
Example: It may be a good idea to design the most parts to be 3d printed instead of CNC milled. The 3d printer is easier to use. It starts with an empty build plate. Modern 3d printers just require a click on "print", no manual calibration is needed. Subtractive methods like CNC milling reuqires the correct positioning of the material block at first. The tools must cut away some material. The block must be big enough in all 3 dimensions. It must be locked in place, at a point, which isn't being to be cut away. The bigger the block is, the more material is going to be wasted. The tool also needs to travel additional routes to cut it away. The requirement to use a CNC mashine is likely a show stopper for contributions to an OSH project.
This design4openness guide collects decisions for a good OSH design in the sense of openness and makability.