
162 Mich. App. 729 (1987)
413 N.W.2d 489
SOUTHFIELD POLICE OFFICERS ASSOCIATION
v.
CITY OF SOUTHFIELD
Docket No. 88574.
Michigan Court of Appeals.
Decided September 9, 1987.
Hiller, Larkey & Hoekenga, P.C. (by Marc M. *731 Susselman), for Southfield Police Officers Association.
Susan P. Ward, for City of Southfield.
Before: J.H. GILLIS, P.J., and SHEPHERD and W.A. PORTER,[*] JJ.
W.A. PORTER, J.
The Southfield Police Officers Association appeals from the decision and order of the Michigan Employment Relations Commission dismissing a charge filed pursuant to the public employment relations act, MCL 423.201 et seq.; MSA 17.455(1) et seq. We affirm in part and reverse in part.
The association is the collective bargaining representative for police officers employed by the City of Southfield. The association alleged in its charge various unfair labor practices committed by the city. Pertinent to this appeal are the following: (1) refusal to bargain over the proposed transfer of job responsibilities in the crime prevention section and the automobile pound to nonunit employees (personnel not represented by the association); (2) refusal to bargain over the proposed subcontracting of the policing of a shopping mall to private security guards; and (3) refusal to engage in grievance proceedings with the association's designated representative. The first two allegations concern the reassignment of job tasks performed at least in part by association members prior to the hearing date in the instant case.
I
The association argues that the city committed an unfair labor practice pursuant to MCL *732 423.210(1)(e); MSA 17.455(10)(1)(e) by refusing to engage in collective bargaining over its proposed reassignment of job functions in the crime prevention section and the automobile pound. Although these functions were being performed by association members as of the date of the hearing in this case, the city proposed to assign nonunit employees to these functions in the future.
An employer subject to PERA may not unilaterally alter the terms and conditions of employment without first exhausting its mandatory duty to bargain. See MCL 423.215; MSA 17.455(15). It is generally established that the duty to bargain extends to the employer's diversion of work to nonunit employees or to the subcontracting of the work to nonemployees. Lansing Fire Fighters Union, Local 421 v Lansing, 133 Mich App 56; 349 NW2d 253 (1984); Plymouth Fire Fighters Ass'n, Local 1811 v Plymouth, 156 Mich App 220; 401 NW2d 281 (1986). Job functions encompassed by the duty to bargain are commonly known as bargaining unit work.
The association here attacks MERC'S determination that the job tasks designated to undergo reassignment were not bargaining unit work. MERC found that the job tasks in question had previously been filled by both unit and nonunit employees. Because these tasks were not "exclusively" the domain of association members, they were not bargaining unit work, and the city's duty to bargain therefore did not attach. The association argues that the so-called rule of exclusivity has no basis in law. We agree.
At the outset, we note that the findings of MERC are conclusive if supported by competent, material, and substantial evidence on the record. Const 1963, art 6, § 28; MCL 423.216(e); MSA 17.455(16)(e). If, however, the decision of MERC is *733 premised upon an error of law, we are not constrained to uphold that decision. West Ottawa Ed Ass'n v West Ottawa Public Schools Bd of Ed, 126 Mich App 306, 313; 337 NW2d 533 (1983), lv den 418 Mich 890 (1983). The question whether a particular subject matter affecting employment falls within the scope of the employer's mandatory duty to bargain is decided on a case-by-case basis. Id., 315.
We are unaware of any published opinions rendered by this Court or by our Supreme Court construing PERA that would govern the association's contention. We note, however, that federal decisions construing the analogous National Labor Relations Act are persuasive authority in questions of the proper interpretation of PERA. West Ottawa Ed Ass'n, supra, 314-315. We add the caveat that the provisions of PERA are to be construed even more liberally in favor of the employees in compensation for the PERA prohibition against striking. Id., 315.
The outer contours of what constitutes bargaining unit work were addressed in AMCAR Division, ACF Industries, Inc v NLRB, 596 F2d 1344, 1349 (CA 8, 1979), where the court adopted the following test from Westinghouse Electric Corp, 150 NLRB 1574; 58 LRRM 1257 (1965), with respect the National Labor Relations Act:
"[W]here the Board has found unilateral contracting out of unit work to be violative of Section 8(a)(5) and (1), it has invariably appeared that the contracting out involves a departure from previously established operating practices, effected [sic] a change in conditions of employment, or resulted [sic] in a significant impairment of job tenure, employment security, or reasonably anticipated work opportunities for those in the bargaining unit."
*734 The key question under this test is whether the proposed unilateral adjustment to work previously performed by the bargaining unit would impose an adverse impact on the unit members. See also Olinkraft, Inc v NLRB, 666 F2d 302, 305 (CA 5, 1982). The dispositive question is not whether the work was performed exclusively by union employees in the past, but rather whether the employer's proposed reassignment would be inconsistent with previously established operating practices, would effect a change in conditions of employment, or result in a significant impairment of job tenure, employment security or reasonably anticipated work opportunities for those in the bargaining unit. This standard is certainly more favorable to the interests of the employees than that applied by MERC in the instant case. Given our Court's avowed adherence to the principle that PERA should be construed more liberally than the National Labor Relations Act, it would be anomalous for us to uphold MERC'S exclusivity rule.[1] We conclude that a proper disposition of this case requires remand for further conclusions of law and, if necessary, further findings of fact consistent with the test applied in AMCAR.
II
The association charged that the city had committed an unfair labor practice by refusing to bargain over its plan to permit private security guards to issue tickets for ordinance violations to juvenile offenders in a shopping mall. This work *735 was performed in part by association members prior to the hearing. MERC dismissed this charge upon its finding that the plan was still tentative since no final decision regarding implementation had been made. Since this finding is supported by competent, material, and substantial evidence, we are bound by it.
The question presented is no different from the well-recognized rule that hypothetical cases should not be decided until such time that the case becomes ripe for adjudication. Eastern Michigan University Chapter of the American Ass'n of University Professors v Morgan, 100 Mich App 219, 231; 298 NW2d 886 (1980), lv den 411 Mich 955 (1981). Generally, a question is not justiciable when the complaining party seeks "a decision, in advance, about a right before it has been actually asserted and tested, or judgment upon some matter which, when rendered, for any reason cannot have practical legal effect upon the then existing controversy." Menominee Co Taxpayers Alliance, Inc v Menominee Co Clerk, 139 Mich App 814, 819-820; 362 NW2d 871 (1984), lv den 422 Mich 977 (1985). This doctrine applies to questions arising in the context of PERA. Morgan, supra, 231. Accordingly, we conclude that MERC did not err in its dismissal on the ground that the charge was premature.
III
The association charged that the city had wrongfully refused to conduct grievance procedures in the presence of a labor consultant, serving as the association's duly appointed representative, who was not a member of the association. MERC concluded that the provisions of the collective bargaining agreement validly limited participation in *736 grievance procedures to members of the association appointed to the grievance committee. We conclude that MERC'S decision ignored the proper legal standard for evaluating a contractual waiver of rights protected under PERA. Section 9 of PERA grants public employees the right to negotiate with their employer "through representatives of their own free choice." MCL 423.209; MSA 17.455(9). Interference with § 9 rights is an unfair labor practice. MCL 423.210(1)(a); MSA 17.455(10)(1)(a). A waiver of a right granted by PERA can only be effected in clear and unmistakable terms. Kent Co Ed Ass'n/Cedar Springs Ed Ass'n v Cedar Springs Public Schools, 157 Mich App 59, 65-67; 403 NW2d 494 (1987); Mid-Michigan Ed Ass'n (MEA-NEA) v St Charles Community Schools, 150 Mich App 763, 770-771; 389 NW2d 482 (1986); Lansing Fire Fighters Union, supra, 65-67. Our review of the collective bargaining agreement convinces us that no waiver occurred. Those terms pertinent to the grievance procedure do no more than provide who may participate as members of the grievance committee. They do not exclude others, including the association's designated representative. Thus, MERC'S decision to dismiss this aspect of the association's charge on the basis of waiver was erroneous.
Affirmed in part, reversed in part, and remanded for further proceedings consistent with this opinion.
NOTES
[*]  Circuit judge, sitting on the Court of Appeals by assignment.
[1]  We note that the exclusivity rule finds support in decisions of MERC. See, e.g., Schoolcraft Community College v Schoolcraft College Ass'n of Office Personnel/MESPA, 1985 MERC Lab Op 253, 258-259, aff'd 156 Mich App 754; 401 NW2d 915 (1986), lv den 428 Mich 895 (1987). Other decisions appear to follow the approach in Westinghouse Electric Corp, supra. See Clinton Co Intermediate School Dist v Clinton Intermediate Ed Ass'n, 1984 MERC Lab Op 529, 531-534.
