(a) Subject to subsection (b) of this section, nothing in this chapter shall affect the authority of any management official of any agency—

(1) to determine the mission, budget, organization, number of employees, and internal security practices of the agency; and

(2) in accordance with applicable laws—

(A) to hire, assign, direct, layoff, and retain employees in the agency, or to suspend, remove, reduce in grade or pay, or take other disciplinary action against such employees;

(B) to assign work, to make determinations with respect to contracting out, and to determine the personnel by which agency operations shall be conducted;

(C) with respect to filling positions, to make selections for appointments from—

(i) among properly ranked and certified candidates for promotion; or

(ii) any other appropriate source; and

(D) to take whatever actions may be necessary to carry out the agency mission during emergencies.

(b) Nothing in this section shall preclude any agency and any labor organization from negotiating—

(1) at the election of the agency, on the numbers, types, and grades of employees or positions assigned to any organizational subdivision, work project, or tour of duty, or on the technology, methods, and means of performing work;

(2) procedures which management officials of the agency will observe in exercising any authority under this section; or

(3) appropriate arrangements for employees adversely affected by the exercise of any authority under this section by such management officials.