The Waffen-SS technically answered to Heinrich Himmler. However, for planning and operations, they were subordnated to the OKW and OKH. The SS had their own replacement system and received preferential treatment for weapons and supply. Command and control of Waffen SS units, as well as their quality and effectiveness, evolved over time. They went from police/security details who were thrust into the field where they faired poorly to gaining near mythological status for achieving tactical victories against extreme odds. In terms of larger strategy, they never called the shots, that was Hitler's prerogative.

http://www.globalsecurity.org/military/world/europe/de-waffen-ss-heer.htm