Cummings to serve as acting Pentagon acquisition head January 13 Stacy Cummings speaks at a 2017 event. She will serve as acting undersecretary of defense for acquisition and sustainment after Jan. 20. (Flavia Hulsey/U.S. Defense Department) WASHINGTON — Stacy Cummings, the acting deputy assistant secretary of defense for acquisition, will temporarily fill the department’s top acquisition office once Joe Biden becomes president, Defense News has learned. Ellen Lord, the undersecretary for acquisition and sustainment, will step down on Jan. 20, with Cummings filling that role until th...