Development of the Sh.I engine resulted in the eleven-cylinder, 160 hp Sh.III, perhaps one of the most advanced rotary engine designs of the war. The D.I fighter also formed the basis for a series of original designs, which by the end of 1917 had reached a peak in the Siemens-Schuckert D.III, which went into limited production in early 1918, and found use in home defense units as an interceptor, due to its outstanding rate of climb. Further modifications improved its handling and performance to produce the Siemens-Schuckert D.IV. Several offshoots of the design included triplanes and a parasol monoplane, but none saw production.