Read this and answer the question

The effect of these differences was accentuated by the pre-war preparations. The Prussian General Staff had drawn up minutely detailed mobilization plans using the railway system, which in turn had been partly laid out in response to recommendations of a Railway Section within the General Staff. The French railway system, with multiple competing companies, had developed purely from commercial pressures and many journeys to the front in Alsace and Lorraine involved long diversions and frequent changes between trains. Furthermore, no system had been put in place for military control of the railways, and officers simply commandeered trains as they saw fit. Rail sidings and marshalling yards became choked with loaded wagons, with nobody responsible for unloading them or directing them to the destination.

What was the Prussian General staff quick to utilize at the onset of the war?
detailed mobilization plans using the railway system