You'll need a PCB Design software to convert a schematic to manufacturing files (like Gerber, NC, ODB++). PCB Design software ensures the electrical connectivity from your schematic and generate files for manufacturing. The primary purpose of FAB 3000 is to verify your final manufacturing files do not contain any specific violations that may cause your boards to fail during fabrication.
Note: Another purpose of FAB 3000 is to combine multiple PCB designs together and place them all into one panel. Most PCB Manufacturers charge per PCB design, so by merging multiple PCB designs together into one design - you save money on manufacturing. https://support.numericalinnovations.com/support/discussions/topics/14000002367