I have made changes to the PCB, including hole sizes, added a couple resistors, etc. I need to save the updated PCB for the next manufacturing run, but obviously need to keep the original PCB to document the last manuf’ing run. Do I create a new project? Use “Save as”? I had to create a whole new project last time, import the board and the schematic – seems like this should be a very common process.
You can put your whole project in some sort of version control system. Git is the most popular but there are many others like SVN, Mercurial, and my favourite, Fossil.
You commit your design via the version control software and then can make any changes you need and make a further commits as your design evolves. You can then flip between all the revisions that you make, revert to previous designs etc. You can tag individual commit points as versions from which you made production runs and restore that design at a few keystrokes.
Git plug-in is available now and will be a built in option in KiCad 9.
When I up issue my boards I do a ‘save as’, give the project a new name and save in a folder within the project directory. So project ABC123 folder will have a i1,i2… folders with the relevant versions within them.
When I want to make new project revision I start from copying project, schematic and PCB files changing their names (in my file manager I can specify new name as NewName.* so all files are ranamed at once). Then I modify schematic, update PCB from schematic and so on.