The Wisconsin Employment Relations Commission (WERC) and Local 2959 of the Wisconsin Council of County and Municipal Employees, No. 40, AFSCME, AFL-CIO (union), appeal a judgment reversing the commission’s determination that Lorraine Reimer, a Kewaunee County employee holding the combined positions of register in probate, probate registrar, and probate court commissioner, was a municipal employee entitled to the collective bargaining rights set forth in the Municipal Employment Relations Act (MERA), secs. 111.70 to 111.77, Stats. They argue that the circuit court erroneously determined that Reimer was precluded from union membership because her positions involve duties falling within the "managerial” exception to MERA. They also argue that the court erroneously concluded that because county judges have the statutory authority to appoint and discharge registers in probate, probate registrars, and probate court commissioners, a special exception exists in determining whether MERA applies to such officials. We agree with the commission and the union on both issues. The judgment is reversed.
In June, 1984, the county filed a petition with the commission that sought to exclude Reimer from the union’s collective bargaining unit. Relying on sec. 111.70(l)(i), Stats., the county argued that Reimer’s duties as register in probate/probate registrar/probate court commissioner were of a supervisory, managerial, or executive nature, and that, there*351fore, she was not a municipal employee falling within the scope of MERA. Section 111.70(l)(i) defines a municipal employee as "any individual employed by a municipal employer other than ... [a] supervisor ... managerial or executive employe.”
The commission determined that Reimer’s function did not involve supervisory, managerial, or executive duties and that, therefore, she was a municipal employee as defined in sec. 111.70(l)(i). In making this determination, the commission noted that because Reimer’s duties were defined by statute, there was little, if any, opportunity for her to affect the formulation, determination, or implementation of management policy.
The commission also determined that Reimer’s budget preparing duties failed to establish that she was a managerial employee. The commission found that Reimer did not possess effective authority to commit the county’s resources. The commission noted that, with one exception, the 1985 budget prepared by Reimer contained the same appropriations for the same kind of expenditures as the 1984 budget that had been prepared by the judge. Consequently, the commission concluded that these duties were ministerial because Reimer’s budgetary duties involved only projecting the cost of continuing current operations.
The county appealed the commission’s decision to the circuit court. The court agreed with the commission that Reimer’s positions did not provide an opportunity to significantly affect the formulation, determination, or implementation of management policy and that, therefore, her duties were not supervisory or executive in nature. However, relying on Eau Claire County v. WERC, 122 Wis. 2d 363, 366, 362 N.W.2d 429, 430-31 (Ct. App. 1984), the court determined that *352Reimer was a managerial employee because she had effective authority to commit the county’s resources. In Eau Claire, we held that a register in probate/probate registrar did have such authority because "by forwarding a recommended budget to the county board, the register in probate ... created an original budget.” Id. at 369, 362 N.W.2d at 432. The circuit court concluded that Eau Claire was controlling because Reimer’s duties included preparing the budget and submitting it to the county board for its approval.
In reversing the commission’s decision, the court determined that the unique nature of Reimer’s positions created a special exception to the normal indicia used to determine whether an employee should be eligible for union membership. The court noted that a judge is empowered by statute to appoint, discharge, and describe the working conditions of registers in probate, probate registrars, and probate court commissioners. Sections 757.72(4), 851.71(1), and 865.065(1), Stats. Therefore, the court concluded that these statutory powers would conflict with an individual’s collective bargaining rights under MERA.
On appeal, the commission and the union contend that the circuit court erroneously applied Eau Claire in determining that Reimer’s budgetary duties demonstrated that she was a managerial employee. Conversely, the county contends that in light of Eau Claire, the court correctly determined that because Reimer prepared and submitted the budget to the county board for its approval, she was a managerial employee. We conclude that the county and the circuit court misinterpret our holding in Eau Claire. We also conclude that the commission’s determination that Reimer is not a managerial employee is supported by *353the evidence. Finally, we conclude that no conflict between the court’s statutory powers and the MERA exists. A judge appointing an individual to such a position would not be bound by the provisions of an employment contract between a union representing that individual and a county if these provisions restricted the constitutionality to discharge its duties.
In reaching our decision, we must examine the underlying facts of this case. No bright-line test exists for determining whether an individual employed as a register in probate, probate registrar, or probate court commissioner is subject to MERA and is therefore eligible for union membership. Rather, this determination involves a case-by-case examination of the duties, responsibilities, and powers of these offices. See Eau Claire, 122 Wis. 2d at 367-68, 362 N.W.2d at 431; see also Village of Whitefish Bay v. WERC, 103 Wis. 2d 443, 448, 309 N.W.2d 17, 20 (Ct. App. 1981).
A two-fold analysis is used to determine whether an employee is "managerial” within the meaning of sec. 111.70(l)(i). Under the first test, a court determines whether the employee participates in the formulation, determination, and implementation of management policy. Eau Claire, 122 Wis. 2d at 367-68, 362 N.W.2d at 431. It is undisputed that Reimer is not a managerial employee under this test. Under the second test, a court determines whether the employee possesses effective authority to commit the employer’s resources. Id. This authority is defined as the power to establish an original budget or to allocate funds for differing program purposes under such a budget. Id. However, the power to make ministerial expenditures is not a factor. Id.
*354In Eau Claire, the issue was whether the managerial exception to MERA involving an employee’s authority to commit the employer’s resources was applicable, in light of the requirement that the county board approve a departmental budget before its implementation. Id. at 368-69, 362 N.W.2d at 432. We concluded that the ability to prepare and submit an original budget to the board was sufficient authority to commit the county’s resources because a contrary finding would have rendered the second test of the managerial analysis meaningless. Id.
The county’s reliance on Eau Claire is misplaced. Eau Claire did not define what budgetary duties an employee must possess to establish that he or she has effective authority to commit an employer’s resources. That issue was not raised. Rather, in Eau Claire we addressed whether the authority to expend an employer’s resources may exist even though ultimate authority to appropriate the funds lies with the board. The language of the decision should not be read as equating the ministerial task of reducing a budget to writing and submitting it to the county board with the authority to prepare an original budget. The two concepts differ in substance if not in form.
Here, the commission determined that preparing and submitting a budget to the county board, standing alone, did not establish managerial status under sec. 111.70(l)(i). In making this determination, the commission refined the meaning of "effective authority to commit an employer’s resources” under the managerial test defining the term "original budget” described in Eau Claire. The commission noted that to be considered managerial, an employee’s budget preparing duties must necessarily involve the authority to determine "the kind and level of services to be *355provided; the kind and number of employees to be utilized in providing services; the kind and number of capital improvements to be made; and the system by which the services will be provided, including the use of outside contractors.”
The interpretation of a statute presents a question of law that is reviewed without deference. Section 227.57(5), Stats. Nevertheless, in light of an agency’s expertise in a given area, we will sustain its interpretation if it rests upon a rational basis and is consistent with the purposes of the statute. City of Milwaukee v. WERC, 71 Wis. 2d 709, 715, 239 N.W.2d 63, 66 (1976); see also sec. 227.57(10), Stats. The commission’s expertise in distinguishing between municipal and managerial employees is well established. City of Milwaukee, 71 Wis. 2d at 714, 239 N.W.2d at 66.
The commission’s interpretation of sec. 111.70(l)(i) is reasonable and consistent with the purposes of MERA, which is to permit municipal employees desiring an opportunity to collectively bargain with the municipal employer. For an employee’s budgetary duties to constitute effective authority to commit an employer’s resources, the employee must possess the discretionary power to determine the type and level of services to be provided and the manner and means by which those services will be delivered.
Formulating a budget, as opposed to merely submitting a budget, involves determining the services required, the number of persons necessary to deliver those services, and the quantity and type of equipment and supplies required to provide those services. Consequently, to possess effective authority *356to commit an employer’s resources, an employee preparing a budget must possess the authority to effectively recommend the amount and the manner in which funds will be expended in support of each of the services provided. This distinction is consistent with the purposes of MERA because it effectively distinguishes those employees who possess managerial interests from those who do not. See Eau Claire, 122 Wis. 2d at 367-68, 362 N.W.2d at 431.
In light of the above, we confirm the commission’s determination that budgetary duties involving the ministerial act of reducing numbers to paper and submitting them to the board fails to meet the test of submitting an original budget. This test focuses on the power to determine the manner and method by which the office discharges its responsibility. Submitting last year’s budget if it reflects the affirmative decisions of the person preparing the budget is sufficient to meet this test. Submitting a budget that does not reflect the decisions of its preparer is not an original budget and fails this test.
We must next determine whether the evidence supports the commission’s determinations that Reimer’s budgetary duties are ministerial and that, consequently, she is not a managerial employee.
In reviewing an agency’s findings, this court applies the same standard as the circuit court. CUNA Mutual v. Wisconsin Dept. of Revenue, 120 Wis. 2d 445, 451, 355 N.W.2d 541, 544 (Ct. App. 1984). Review is confined to the record. Section 227.57(1), Stats. An agency’s finding of fact will not be disturbed if supported by substantial evidence. Gilbert v. State, 119 Wis. 2d 168, 195-96, 349 N.W.2d 68, 80 (1984); sec. 227.57(6), Stats. Substantial evidence is "such relevant *357evidence as a reasonable mind might accept as adequate to support a conclusion.” Gilbert, 119 Wis. 2d at 195-96, 349 N.W.2d at 80. If more than one inference can be reasonably drawn from the evidence, the agency’s determination is conclusive. Vocational Tech. v. DILHR, 76 Wis. 2d 230, 240, 251 N.W.2d 41, 46-47 (1977); sec. 227.57(6), Stats.
The commission’s determination that Reimer’s budgetary duties failed to confer managerial status is supported by substantial evidence. This determination was based upon the testimony of Reimer and a county board member as well as various documents that described Reimer’s official duties. With one minor exception, the 1985 budget Reimer prepared contained the same appropriations for the same type of expenditures as the 1984 budget prepared by the judge. Based upon this evidence, the commission found that Reimer’s authority was limited to adopting an existing budget with adjustments for the anticipated changes in the cost of supplies. Consequently, her budgetary duties primarily involved projecting the cost of continuing current operations. Therefore, the act of preparation did not reflect policy decisions Reimer made. The commission determined that Reimer’s budgetary duties were ministerial, and did not confer managerial status and that, accordingly, she was a municipal employee within the purview of MERA. Because these findings are supported by the evidence and reasonable inferences drawn therefrom, we are required to accept them as conclusive even though a contrary finding may be reached from the same evidence. Id.
Finally, the county argues that permitting Reimer to invoke her collective bargaining rights under MERA would not only violate the separation of *358powers doctrine and interfere with a judge’s statutory authority to appoint and discharge, but also disrupt the working conditions of registers in probate, probate registrars, and probate court commissioners. Sections 757.72(4), 851.71(1), and 865.065(1), Stats.
Whenever possible, MERA must be harmonized with other provisions of the law. Glendale Prof. Policemen’s Ass’n v. City of Glendale, 83 Wis. 2d 90, 103-04, 264 N.W.2d 594, 601 (1978); see also Muskego-Norway Con. Sch. v. WERB, 35 Wis. 2d 540, 556, 151 N.W.2d 617, 624-25 (1967). The separation of powers doctrine prohibits the legislature from acting in certain spheres that are exclusively within the province of the courts. State v. Holmes, 106 Wis. 2d 31, 46, 315 N.W.2d 703, 710 (1982). The doctrine does not, however, prohibit the legislature from exercising its legislative powers in areas that may in some way affect the judicial branch. Id. The legislature’s declarations must be implemented insofar as they do not embarrass the courts or impair their constitutional function. Id.
Here, MERA can be harmonized with the separation of powers doctrine and a court’s statutory authority to appoint persons to and discharge them from the offices of register in probate, probate registrar, and probate court commissioner. Provisions in a labor contract that are contrary to law are unenforceable. WERC v. Teamsters Local No. 563, 75 Wis. 2d 602, 612, 250 N.W.2d 696, 701 (1977). Thus, any provision in a collective labor agreement between the union and the county that hampers a court in its operation or interfers with its constitutional functions would be void. Furthermore, any contractual provision that *359conflicts with the authority vested in a judge to appoint or remove someone from such a position would also be void. Reimer may invoke her rights under MERA and negotiate with the county on those labor matters not entrusted to the courts.
By the Court. — Judgment reversed.1
The union contends that it was denied due process of law because the circuit court rendered its decision without a hearing or the submission of trial briefs. Because we conclude that Reimer is not a managerial employee within the meaning of sec. 111.70(l)(i) and that conclusion is dispositive of this appeal, we do not address this issue. See Gross v. Hoffman, 227 Wis. 296, 300, 277 N.W. 663, 665 (1938).