70 ILCS 1215/3
The Civil Service Board shall within ninety days after this act goes into effect, classify all offices and places of employment in said Park Employees' and Retirement Board Employees' Annuity and Benefit Fund system with reference to the duties thereof and for the purpose of establishing grades and of fixing and maintaining standards of examinations hereinafter provided for. The offices and places so classified shall constitute the classified civil service of such Park Employees' and Retirement Board Employees' Annuity and Benefit Fund system and no appointments, promotions, transfers, reductions in grade or removal therefrom shall be made except under and according to the provisions of this act, and of the rules hereinafter mentioned. As a part of such classified service all officers and employees of said Board of Trustees other than those specifically exempted under the provisions of Section 13 of this Act shall be included. The Civil Service Board shall ascertain and record the duties of each office and place in the classified civil service and designate the grade of each position. Each grade shall comprise offices and places having substantially similar duties. They shall also record the lines of promotion from each lower grade to a higher grade wherever the experience derived in the performance of the duties of such lower grade tends to qualify for the performance of duty in such higher grade. The Civil Service Board shall by rules prescribe standards of efficiency for each grade and for examinations of candidates for appointment thereto.
For the purpose of establishing standards as basis for uniformity of pay and title for all offices and places of employment classified in the same grade, it shall be the duty of the Civil Service Board to prescribe by rule the maximum and minimum rate of pay for each grade and the title thereof, for the guidance of the Board of Trustees in determining the actual pay for each office or place of employment, and to report to the Board of Trustees annually and at such other times as they may direct, the name and address of each officer and employee paid more than the maximum or less than the minimum rate of pay prescribed for his or her grade or designated by a title other than that prescribed for his or her grade by the Civil Service Board. It shall be the duty of the Board of Trustees, within thirty days after receiving such report, to change the pay or title of every officer or employee so reported out of grade to conform to the standards of title and pay prescribed by the Civil Service Board for the guidance of the Board of Trustees for the grade in which the position held by such officer or employee is classified. The Civil Service Board shall standardize employment in each grade and make and keep a record of the relative efficiency of each officer and employee in the classified civil service. The Civil Service Board shall provide by rule methods for ascertaining and verifying the facts from which such records of relative efficiency shall be made which shall be uniform for each grade in the classified civil service.
70 ILCS 1215/3