For purposes of this chapter, "manager" means any employee who:
(1) Formulates statewide policy or directs the work of an agency or agency subdivision;
(2) Is responsible to administer one or more statewide policies or programs of an agency or agency subdivision;
(3) Manages, administers, and controls a local branch office of an agency or agency subdivision, including the physical, financial, or personnel resources;
(4) Has substantial responsibility in personnel administration, legislative relations, public information, or the preparation and administration of budgets; or
(5) Functionally is above the first level of supervision and exercises authority that is not merely routine or clerical in nature and requires the consistent use of independent judgment.
Members of the Washington management service may be included in a collective bargaining unit established under chapter
41.80 RCW, except as provided in RCW
41.80.430.