Abstract: A production method for producing a heat exchanger assembly, which may serve for at least one of cooling and heating a functional component via a heat exchanger fluid, may include first providing a duct flat body, which may have a flow duct comprising a clear flow cross section, through which heat exchanger fluid may be flowable. The method then may include forming the duct flat body as part of a rolling process or as part of a roller burnishing process to form a bent cylinder jacket-shaped heat exchanger housing. The method then may include arranging the bent heat exchanger housing on a jacket surface of the functional component, and fixing the heat exchanger housing on the jacket surface of the functional component.