10 U.S.C. § 191. — Secretary of Defense: authority to provide for common performance of supply or service activities

((a)) ** .—** Whenever the Secretary of Defense determines such action would be more effective, economical, or efficient, the Secretary may provide for the performance of a supply or service activity that is common to more than one military department by a single agency of the Department of Defense.

((b)) ** .—** Any agency of the Department of Defense established under subsection (a) (or under the second sentence of (as in effect before )) for the performance of a supply or service activity referred to in such subsection shall be designated as a Defense Agency or a Department of Defense Field Activity.