Some Artilleriedepots were intended to manufacture rifle cartridges in case of mobilization.
Posen, Breslau, Königsberg, Danzig, Stettin, Hannover, Erfurt, Cöln (Köln), Coblenz (Koblenz), Mainz, Metz and Straßburg had a large set of equipment. During peacetime they manufactured 2 million cartridges every 2-3 years, to keep them trained in doing this. (Metz and Strassburg located in Alsace)
Cüstrin (Küstrin), Wesel and Ulm had a small equipment set and produced 250 000 cartridges each year.
That is what the regulation (DVE 260 of 1901) said about Patrone 88. I do not know to what degree this was actually done.
Edit: I forgot Berlin in the first list which had a triple equipment set compared to the others.