50 ILCS 742/30
Promotion examinations that include components consisting of written examinations, seniority points, ascertained merit, or subjective evaluations shall be administered as provided in Sections 35, 40, 45 and 50. The weight, if any, that is given to any component included in a test may be set at the discretion of the appointing authority provided that such weight shall be subject to modification by the terms of any collective bargaining agreement in effect on the effective date of this Act or thereafter by negotiations between the employer and an exclusive bargaining representative. If the appointing authority establishes a minimum passing score, such score shall be announced prior to the date of the promotion process and it must be an aggregate of all components of the testing process. All candidates shall be allowed to participate in all components of the testing process irrespective of their score on any one component. The provisions of this Section do not apply to the extent that they are inconsistent with provisions otherwise agreed to in a collective bargaining agreement.
50 ILCS 742/30