enactment of this Act. 903. Clarification of authority of Under Secretary of Defense for Acquisition and Sustainment with respect to service acquisition programs for which the service acquisition executive is the milestone decision authority Effective on February 1, 2018, and immediately after the coming into effect of the amendment made by section 901(b) of the National Defense Authorization Act for Fiscal Year 2017 ( Public Law 114–328 ), subsection (b)(6) of section 133b of title 10, United States Code, as added by such section 901(b), is amended by striking supervisory authority and inserting advisory authority . 904. Executive Schedule matters relating to Under Secretary of Defense for Acquisition and Sustainment (a) Inapplicability of pending amendment The amendment to be made by section 901(h) of the National Defense Authorization Act for Fiscal Year 2017 ( Public Law 114–328