Petition for Review of an Order of the Illinois Labor Relations Board.
 The opinion of the court was delivered by: Justice Karnezis
 Petitioner, County of Cook (the County), appeals from an order issued by respondent, the Local Panel of the Illinois Labor Relations Board (ILRB), regarding the collective bargaining rights of attending physicians (attendings) employed by Oak Forest Hospital (the hospital), a hospital operated by the County. The ILRB determined that the attendings are not managerial employees pursuant to section 3(j) of the Illinois Public Labor Relations Act (the Act) (5 ILCS 315/3(j) (West 2002)) and that the attendings in the hospital's Department of Rehabilitative Medicine (rehabilitation attendings) are also not supervisory employees under section 3(r) of the Act (5 ILCS 315/3(r) (West 2002)). As a result, pursuant to the Act, both the attendings and rehabilitation attendings were eligible to participate in collective bargaining and to vote on the election of respondent, Service Employees International Union - Local 74 HC (the union), as their collective bargaining representative.
 The County argues on appeal that the ILRB erred in its determinations because (1) the attendings engaged predominantly in executive and managerial functions and were, therefore, managerial employees pursuant to section 3(j); and (2) the rehabilitation attendings, in addition to being managerial employees, were supervisory employees pursuant to section 3(r) based on their direction and evaluation of the residents in their department. We affirm.
 In April 2002, the union filed a representation/certification petition with the ILRB seeking to represent a bargaining unit of all full- and regular part-time attending physicians employed by the County at the hospital. The petition also concerned three outlying clinics but the ILRB's findings regarding the clinics are not at issue here. The County opposed the petition, arguing that the attendings were managerial or supervisory employees within the meaning of the Act and should be excluded from collective bargaining. An eight-day hearing was held before an administrative law judge (ALJ). The parties stipulated that the hospital is a public employer and that the attendings are professional employees within the meaning of the Act. The parties also stipulated that certain individuals, including the hospital's chief operating officer, its medical director, its director of oncology, its chief of dentistry and the chairmen of the hospital's medical administration division departments, be excluded from the petitioned-for bargaining unit because they are managerial or supervisory employees under the Act.
 The hospital is part of a health care network operated by the Cook County Board of Commissioners (Board) through the Cook County Bureau of Health Services (Bureau). The Bureau's bylaws provide that the Board is responsible for control and management of the hospital's property, funds and operations. Under the bylaws, the Board has the power to amend the Bureau's bylaws; appoint, terminate or modify the medical staff at the hospital; receive and act upon budget recommendations; review and approve finances, costs and charges and general wage and salary increases and decreases; make, amend, repeal or approve overall policies for operation of the hospital; and approve the hospital's medical staff's rules and regulations.
 The hospital is comprised of several divisions and managed by a chief operating officer (COO) appointed by the Board. The COO has authority and responsibility for the day-to-day affairs of the hospital, subject to the Bureau's bylaws and authority of the Bureau chief. Pursuant to the bylaws, the COO is responsible for presenting "recommendations" to the Board regarding operations and long-range planning of the hospital and for carrying out the Board's policies and directives. Among other duties, the COO must present contracts and purchase agreements, annual budget recommendations and recommendations from the medical staff regarding staff appointments or termination of clinical privileges to the Board for approval.
 One of the hospital divisions is the medical administration division, which is overseen by a medical director, who is appointed by and reports directly to the COO. The medical director works under the direction of the COO in consultation with the medical staff. The medical staff is comprised of all Illinois-licensed doctors of medicine, osteopathy, dentistry and podiatry with hospital privileges and includes approximately 60 physicians, including 48 attendings and 12 department chairs. Attendings are the primary care physicians at the hospital. The departments in the medical administration division are headed by department chairs who report to the medical director and are responsible for the operation of his or her department. One attending in each department is designated to act as that department's chair when the chair is absent, and three medical staff members are elected to serve as president, vice president and secretary/treasurer of the medical staff.
 The Bureau's bylaws assign "the overall responsibility for the quality of the professional services provided" within the hospital to the medical staff. The Board gives the medical staff "the responsibility for the preservation and improvement of the quality and efficiency of patient care provided" in the hospital and requires the medical staff to conduct activities to fulfill that responsibility and to adopt medical staff bylaws, as approved by the Board. The medical staff bylaws state that the medical staff is "responsible for the quality of medical care in the Hospital and accepts and discharges this responsibility subject to the ultimate authority of the Board of Commissioners of Cook County." Pursuant to those bylaws, the medical staff's purposes include initiating and maintaining rules and regulations for the governance of the medical staff and providing a means through which it may participate in the hospital's policy-making and planning process and discuss issues concerning the medical staff and the hospital with the Board, Bureau chief and the COO.
 The medical staff bylaws provide for department and hospital-wide committees set up to carry out the medical staff's responsibilities. Attendings are expected to serve on at least one committee and most do so. Only four attendings serve on no committee. Few of the committees meet more than once a month and some meet for as little as a half hour every two to three months, as needed. Committee decisions are reached by consensus among the committee members and, if consensus cannot be reached, a formal vote is taken. A committee's recommendations are presented to the medical executive committee for its review. If approved, the medical executive committee submits the recommendation to the COO and joint conference committee for review. The joint conference committee, which is composed of representatives from the Board, hospital administration and medical staff, acts as "a medical administrative liaison committee and an official point of contact" between the Board, medical staff and COO.
 Attendings are expected to attend at least two of the quarterly medical staff meetings each year and 50% of their department's meetings, both the monthly hour-long all-staff meeting and the thrice weekly half hour attendings-only meeting. Decisions reached at the all-staff meetings are submitted to the medical director and Medical Executive Committee and those reached during the attendings-only meetings are submitted to the medical director and the COO. Attendings typically spend 10% of their work time engaged in committee and department meeting activities.
 The County asserted that the attendings' committee activities, their participation in department meetings and their development of individual patient-care treatment plans by which they issue orders and direct other hospital personnel are evidence of their managerial status. The ALJ determined that the attendings' work in department and committee meetings was executive and management decisions but that the attendings' decision making in the meetings was not final or independent and did not constitute a predominant part of their activity because patient-care duties took from 50% to 95% of the attendings' working time. As a result, the ALJ found that, although the attendings did direct the effectuation of management policies and procedures, they did not meet the Act's definition of managerial employees because they were not engaged predominantly in executive and management functions.
 The County also argued that the rehabilitation attendings, in addition to being managerial employees, acted as supervisors of the residents working in the rehabilitation department. The ALJ determined that the rehabilitation attendings did not have the supervisory authority to discipline the residents in their department or to effectively recommend such discipline and that their direction of the residents did not amount to the authority to substantially affect the residents' terms and working conditions. As a result, the ALJ found that the rehabilitation attendings did not exercise supervisory authority over the residents in their department, let alone for a preponderance of their work time as required under the Act, and that they were, therefore, not supervisors. Based on these findings, the ALJ recommended that all full- and regular part-time attendings employed by the County at the hospital, excluding the attendings previously stipulated to as being managers and supervisors, be eligible to vote on representation by the union and that an election be ordered.
 The County filed exceptions to the ALJ's recommended decision and order, and the ILRB heard oral argument. The ILRB accepted the ALJ's recommendation. Following an election, the ILRB certified that the union was the exclusive representative of the salient attendings for the purposes of collective bargaining ...