The Milwaukee Police Association and Marvin Lund seek review of a decision of the court of appeals1 affirming an order of the circuit court that vacated an arbitration award ordering that Mr. Lund be transferred from patrolman to an acting detective status in the Milwaukee Police Department.
The basic dispute in this case centers around the authority of the arbitrator to make the award. The opinions of the lower courts, however, focused on the arbitra-bility of the grievance itself. As a result, we will also address the question of the arbitrability of the grievance. We conclude that although the grievance was arbitrable, the arbitrator lacked the authority to enter the award made. We accordingly affirm the decision of the court of appeals.
I.
Marvin Lund was a patrolman in the Milwaukee Police Department from November, 1960 until February, 1970 when he was transferred to the vice squad where he was assigned duties as “acting detective.”2 In April, 1974 he was transferred to the detective bureau maintaining his status as an acting detective. On October 12, 1975 Mr. Lund was transferred to District No. 7 and was assigned duties as a patrolman.
*18Mr. Lund filed a grievance alleging that his transfer to District No. 7 was a disciplinary measure in violation of the collective bargaining agreement entered into by the City of Milwaukee and the Professional Policeman’s Association (now the Milwaukee Police Association) effective from November 3, 1974 to October 31, 1976.
The grievance was processed through the procedure provided for in the collective bargaining agreement. The dispute remained unresolved and the matter was brought before an arbitrator selected from a panel of arbitrators provided by the Wisconsin Employment Relations Commission. The City contended before the arbitrator that the arbitrator had no authority to grant the relief requested.
The arbitrator framed the issue to be decided as follows:
“Was the reassignment of the grievant from his assignment at the Detective Bureau to Patrolman in the 7th District proper under the terms of the parties’ Collective Bargaining Agreement?”
After reviewing the evidence submitted at the hearing, the arbitrator ruled that:
“The reassignment of the grievant from his assignment at the Detective Bureau to Patrolman in the 7th District violates the terms of the parties’ Collective Bargaining Agreement. The Arbitrator directs the Employer to return the grievant to the Detective Bureau effective with the date of this Award; and further directs that the grievant be placed in his former capacity of Acting Detective.”
In reaching his determination that a violation of the collective bargaining agreement had occurred, the arbitrator initially concluded that the grievant had in fact *19been transferred rather than merely reassigned3 and that grievances based on transfers alleged to be unfair or which showed favoritism were arbitrable under the contract. The arbitrator also found that the motivation behind the transfer was to discipline the employee. The arbitrator, after reviewing the evidence, found that the Association challenged the transfer on disciplinary grounds ruling that the issue was therefore properly submitted to him. After finding that no charges had been filed by the Chief of Police with the Police and Fire Commission against the grievant, the arbitrator ruled that a transfer for disciplinary reasons was arbitrable pursuant to Part III, Section I. A. 1. of the agreement which provides in part:
“Matters of departmental discipline involving application of the rules or regulations of the Chief of Police which are not subject to appeal to the Board of Fire and Police Commissioners, shall constitute a grievance under the aforementioned provisions and matters of departmental discipline involving application of the rules or regulations of the Chief of Police which are subject to appeal to the Board of Fire and Police Commissioners shall not constitute a grievance under the aforementioned provisions.”
The arbitrator then ruled that the discipline and transfer provision of the contract were valid and enforceable. Although there existed no “acting detective” classification under the collective bargaining agreement, the arbi*20trator concluded that if a violation of the contract existed, he would have the authority to order an appropriate remedy including the restoration of the grievant to his former status as an acting detective. The transfer was found to be arbitrary and therefore unfair.
II.
The City asserts that the arbitrator did not have the authority to arbitrate the grievance filed by Mr. Lund. However, the motion to vacate the arbitration award did not challenge the authority of the arbitrator to hear the grievance.4 The motion stated that “. . . an arbitration award was entered . . . settling a controversy that existed between the . . . parties ... in accordance with the arbitration provisions of the Wisconsin Statutes.” Nevertheless, the circuit court and the court of appeals ruled that the grievance in this case was not arbitrable.
While there is a broad presumption of arbitrability, the interpretation of the arbitration clause remains a judicial function unless the parties voluntarily submit the question of arbitrability to the arbitrator. Intern U. Of Operating Engineers, Local Union No. 139 v. Carl A. Morse, Inc., 529 F.2d 574, 580 (7th Cir. 1976). From the limited record before this court, it cannot be determined whether the parties submitted the question of the arbitrability of the dispute to the final and binding decision of the arbitrator. The agreement does not expressly or impliedly give the arbitrator the authority to determine the scope of his authority to make a binding determination as to arbitrability. Although the arbi*21trator noted the City’s objection to the power of the arbitrator to arbitrate the dispute and to restore Mr. Lund to his status as an acting detective, it is not apparent whether the arbitrator’s determination on the arbi-trability issue was intended to be final and binding on the parties. This can be of substantial importance because, as this court has stated:
“If the parties submitted the issue of arbitrability to the arbitrators for final and binding decision, the scope of review of the award on the issue of arbitrability would be limited, as is the scope of review of the merits of the award.
“If the parties submitted the merits to the arbitrators and at the same time challenged the arbitrability of the question and reserved the right to challenge in court an adverse ruling on arbitrability, the court would decide the issue of arbitrability de novo.” Jt. School Dist. No. 10 v. Jefferson Ed. Asso., 78 Wis.2d 94, 106, 253 N.W.2d 536 (1977).
Because we conclude that the grievance involved in this case was arbitrable, even upon de novo judicial review, we need not determine whether the issue of arbi-trability of the grievance was subject to the arbitrator’s final and binding decision.
In Denhart v. Waukesha Brewing Co., 17 Wis.2d 44, 51, 119 N.W.2d 490 (1962), this court adopted the language from one of the decisions forming a part of the now famous “Steelworkers Trilogy”5 which outlined the court’s role in determining when an issue should be submitted to an arbitrator when the collective bargaining agreement provides that all questions of contract interpretation are for the arbitrator. The United States Supreme Court stated:
*22“The function of the court is very limited when the parties have agreed to submit all questions of contract interpretation to the arbitrator. It is confined to ascertaining whether the party seeking arbitration is making a claim which on its face is governed by the contract. ... In these circumstances the moving party should not be deprived of the arbitrator’s judgment, when it was his judgment and all that it connotes that was bargained for.” United Steelworkers Of America v. American Mfg. Co., 863 U.S. 564, 567 (1960).
When the court determines arbitrability, it is limited to considering whether the arbitration clause can be construed to cover the grievance on its face and whether any other provision of the contract specifically excludes it. Jt. School District No. 10 v. Jefferson Ed. Asso., 78 Wis.2d at 111.
Neither of the lower courts had the benefit of this court’s recent decision in Milwaukee Police Asso. v. Milwaukee, 92 Wis.2d 145, 285 N.W.2d 119 (1979) when making their rulings in this case.
In Milwaukee Police Asso. v. Milwaukee, supra, this court had before it the same collective bargaining agreement, and hence, the same arbitration clause at issue in this case. The arbitration clause provides:
“1. Differences involving the interpretation, application or enforcement of the provisions of this Agreement or the application of a rule or regulation of the Chief of Police affecting wages, hours, or conditions of employment and not inconsistent with the 1911 Special Laws of the State of Wisconsin, Chapter 586, and amendments thereto shall constitute a grievance under the provisions set forth below.”
This is an expansive arbitration clause covering a broad class of disputes arising out of the “interpretation, application or enforcement” of the agreement. In reviewing de novo the arbitrability of the Chief of Police’s power to transfer employees under this collective bargaining agreement, the court held in Milwaukee Police Asso. v. *23Milwaukee, that because the parties disagreed as to the interpretation of the Chief of Police’s authority to transfer, and the authority of the Chief of Police to transfer employees was provided for in the contract, there existed a “ ‘difference involving the interpretation’ of the Agreement.” 92 Wis.2d at 153. As a result it was held that the grievance was covered by the arbitration clause and was subject to arbitration. 92 Wis.2d at 152-153.
In that case it was nowhere disputed that a transfer was involved. In this case, however, there is a dispute as to whether Mr. Lund was in fact transferred or merely “reassigned.” We believe that whatever the term used, the underlying question is whether the Chief of Police was limited by the collective bargaining agreement in laterally moving Mr. Lund from acting detective to patrolman. The City also argues that the “reassignment” of the grievant was not for disciplinary reasons and that the Chief of Police had the unrestricted power to make the reassignment. Under the rationale of Milwaukee Police Asso. v. Milwaukee, supra, even upon a de novo review of the arbitrator’s decision as to the arbitrability of the grievance, the grievance in this case was arbitrable because a difference involving the interpretation of the agreement has arisen. Milwaukee Police Asso. v. Milwaukee, 92 Wis.2d at 153.
III.
The authority of the arbitrator to hear a grievance is not the same as the authority of the arbitrator to make a particular award and the distinction between the two concepts must remain clear. The collective bargaining agreement may permit or require the arbitrator to hear a dispute, but it may also restrict him from reaching a particular result by limiting his powers of review or *24relief. Christensen, Labor Arbitration And Judicial Oversight, 19 Stan. L.R. 671, 686 (1967) (Book Review: R. W. Fleming, The Labor Arbitration Process (1965) and P. R. Hays, Labor Arbitration: A Dissenting View (1966)). This distinction has been recognized by this as well as other courts. See, Milw. Bd. Sch. Dirs. v. Milw. Teachers’ Ed. Asso., 93 Wis.2d 415, 287 N.W.2d 131 (1980); Milwaukee Police Asso. v. Milwaukee, supra; WERC v. Teamsters Local No. 56S, 75 Wis.2d 602, 250 N.W.2d 696 (1977); Jt. School Dist. No. 10 v. Jefferson Ed. Asso., 78 Wis.2d 94, 253 N.W.2d 536 (1977); Truck Drivers & Helpers Union Local 784 v. Ulry-Talbert Co., 330 F.2d 562 (8th Cir. 1964) ; Textile Workers Union Of America v. American Thread Co., 291 F.2d 894 (4th Cir. 1961); Electronics Corp. Of Am. v. Electrical Workers Local 272, 492 F.2d 1255 (1st Cir. 1975); World Airways, Inc. v. International Brotherhood Of Teamsters Airline Division, 578 F.2d 800 (9th Cir. 1978) (Per Curiam).
The dispositive question then, is whether the award directing that the grievant be transferred back to acting detective status was within the. authority of the arbitrator. We start from the premise that an arbitrator’s award is presumptively valid, and it will be disturbed only where its invalidity is demonstrated by clear and convincing evidence. Milw. Bd. Sch. Dirs. v. Milw. Teachers’ Ed. Asso., 93 Wis.2d at 422; Stradinger v. City of Whitewater, 89 Wis.2d 19, 37, 277 N.W.2d 827 (1979).
Judicial review of an arbitrator’s decision is quite limited. The merits of the arbitration award are not within the province of courts on review. “The refusal of courts to review the merits of an arbitration award is the proper approach to arbitration under collective bargaining agreements.” United Steelworkers Of America *25v. Enterprise Wheel & Car Corp., 363 U.S. 593, 596 (1960). We are therefore bound to accept the arbitrator’s finding that Marvin Lund was transferred, for disciplinary reasons. We will not review the arbitrator’s finding that the actions of the Chief of Police constituted a transfer and not a “reassignment.” The definitions of the terms “transfer” and “discipline” can be given a broad or narrow meaning, but the interpretation of those terms given by the arbitrator is the interpretation bargained for by the parties. Denhart v. Waukesha Brewing Co., 17 Wis.2d at 51. The decision of the arbitrator will not be disturbed for an error of law or fact. Joint School District No. 10 v. Jefferson Ed. Asso., 78 Wis.2d 94, 117-118, 253 N.W.2d 536 (1977).
The arbitrator’s power to make an award is not unlimited. The power of the arbitrator is derived from the contract and is limited by the terms of the contract:
“When an arbitrator is commissioned to interpret and apply the collective bargaining agreement, he is to bring his informed judgment to bear in order to reach a fair solution of a problem. This is especially true when it comes to formulating remedies. . . . Nevertheless, an arbitrator is confined to interpretation and application of the collective bargaining agreement; he does not sit to dispense his own brand of industrial justice. He may of course look for guidance from many sources, yet his award is legitimate only so long as it draws its essence from the collective bargaining agreement. When the arbitrator’s words manifest an infidelity to this obligation, courts have no choice but to refuse enforcement of the award.” United Steelworkers Of America v. Enterprise Wheel & Car Co., 363 U.S. at 597; see also, Alexander v. Gardner-Denver Co., 415 U.S. 36, 53-54 (1974).
When a grievance is properly before the arbitrator for his decision, the court will overturn the award made when there has been a perverse misconstruction or positive misconduct plainly established, or if the award is *26illegal or violates a strong public policy or if there is a manifest disregard of the law. Milw. Bd. Sch. Dirs. v. Milw. Teachers’ Asso., 93 Wis.2d at 422; Jt. School Dist. No. 10 v. Jefferson Ed. Asso., 78 Wis.2d 94, 117-118, 253 N.W.2d 536 (1977). The agreement between the parties in this case provided that the “arbitration award shall be reduced to writing, subject to Sections 298.08 through and including 298.15 of the Wisconsin Statutes.” Sec. 298.10, Stats. (1973) provided for the vacation of an arbitrator’s award under approximately the same circumstances allowed at common law.
“298.10. Vacation of award, rehearing by arbitrators. (1) In either of the following cases the court in and for the county wherein the award was made must make an order vacating the award upon the application of any party to the arbitration:
“(a) Where the award was procured by corruption, fraud or undue means;
“ (b) Where there was evident partiality or corruption on the part of the arbitrators, or either of them;
“ (c) Where the arbitrators were guilty of misconduct in refusing to postpone the hearing, upon sufficient cause shown, or in refusing to hear evidence pertinent and material to the controversy; or of any other misbehavior by which the rights of any party have been prejudiced.
“ (d) Where the arbitrators exceeded their powers, or so imperfectly executed them that a mutual, final and definite award upon the subject matter submitted was not made.”
We must look to whether the arbitrator exceeded the limits of his power under the contract. If the arbitrator in effect undertook to amend the contract, to substitute., his own discretion for that vested in one or another of the parties or if the arbitrator acted to dispense his own. brand of justice the award will be vacated. Timkin Co v. Local Union No. 1123, United Steelworkers Of America, AFL-CIO, 482 F.2d 1012, 1014-1015 (6th Cir. *271974); Detroit Coil Co. v. Intern. Ass’n. of M. & A., Workers, Lodge #82, 594 F.2d 575 (6th Cir.), cert. denied 444 U.S. 840 (1979). The arbitrator is free to give his own construction to ambiguous language in the collective bargaining agreement but he is without authority to disregard or modify plain and unambiguous provisions. Monogahela Power Co. v. Local No. 2332 International Bro. Of El. Workers, 566 F.2d 1196, 1199 (4th Cir. 1975). The award must “draw its essence” from the collective bargaining agreement. Washington-Baltimore Newspaper Guild v. Bureau Of National Affairs, 97 L.R.R.M. 3068, 3069 (D.D.C. 1978).
With these principles in mind we must analyze the relevant contract provisions to determine whether the arbitrator exceeded the outer bounds of his power.
The collective bargaining agreement in the present case provides that certain rights are to be considered “management rights.” In Part II C., it is provided:
“. . . C. MANAGEMENT RIGHTS. 1. The Association recognizes the right of the City and the Chief of police to operate and manage their affairs in all respects in accordance with the laws of Wisconsin, ordinances of the City, Constitution of the United States and Section 111.70 of the Wisconsin Statutes. The Association recognizes the exclusive right of the Chief of Police to establish and maintain departmental rules and procedures for the administration of Police Department during the term of this Agreement provided that such rules and procedures do not violate any of the provisions of this Agreement. . . .
“5. The City and the Chief of Police shall determine work schedules and establish methods and processes by which such work is performed.
“6. The City and Chief of Police shall have the right to transfer employes within the Police Department in a manner most advantageous to the City.
“7. Except as otherwise specifically provided in this Agreement, the City, the Chief of Police and the Fire and Police Commission shall retain all rights and authority to which by law they are entitled. . . .
*28“11. The association pledges cooperation to the increasing of departmental efficiency and effectiveness. Any and all rights concerning the management and direction of the Police Department and the police force shall be exclusively the right of the City and the Chief of Police unless otherwise provided by the terms of this Agreement as permitted by law.”
To the extent provided for in the agreement these rights are vested exclusively in the City and Chief of Police, and the arbitrator has no power to substitute his judgment or make an award where the power of decision-making is vested in the management.
The agreement also limits the arbitrator’s authority. The grievance and arbitration provisions of the contract detail the restrictions placed on the arbitrator.
“Part III. GRIEVANCE AND ARBITRATION PROCEDURE ... II. GRIEVANCE ARBITRATION. . . . D. The arbitrator shall neither add to, detract from, nor modify the language of the Agreement or of the rules and regulations in arriving at a determination of any issue presented that is proper for final and binding arbitration within the limitations expressed herein. The arbitrator shall have no authority to grant wage increases or wage decreases.
“E. The arbitrator shall expressly confine himself to the precise issues submitted for arbitration and shall have no authority to determine any other issue not so submitted to him or to submit observations or declarations of opinion which are not directly essential in reaching the determination.
“F. In reviewing any difference over application of a departmental rule or regulation under this grievance and arbitration procedure the arbitrator shall take into account the special statutory responsibilities granted to the Chief of Police under the 1911 Special Laws of the State of Wisconsin, Chapter 586, and amendments thereto. The arbitrator shall not impair the ability of the Chief of Police to operate the department in accordance with the statutory responsibilities under the Special Laws *29of the State of Wisconsin, Chapter 586, and amendments thereto . .
Chapter 586, Laws of 1911, as amended, is found in sec. 62.50 (23), Stats. 1977, and provides:
“62.50. Police and fire departments in first class cities . . . (23) Duties OF chief. The chief engineer of the fire department and the chief of police of said cities, shall be the head of their respective departments. The chief of police shall cause the public peace to be preserved and see that all laws and ordinances of the city are enforced. The chief shall be responsible for the efficiency and general good conduct of the department under his control. The chief of each department shall have the power to regulate his or her respective department and shall prescribe rules for the government of its members. Any rule or regulation prescribed by a chief shall be subject to review and suspension by the board. Each of the chief’s shall have the custody and control of all public property pertaining to their respective departments and everything connected therewith and belonging thereto. . . .” See, Milwaukee Police Asso. v. Milwaukee, 92 Wis.2d at 154.
This court in interpreting the forerunner of this provision has stressed the breadth of the management discretion vested in the Chief of Police. The Chief “has broad powers in order to . . . supervise the members of the department.” State ex rel. Kuszewski v. Board Of F. & P. Comm., 22 Wis.2d 19, 25, 125 N.W.2d 334 (1963). Although other provisions of this statute limit the power of the Chief to discipline, this limitation is to be strictly construed.
“The members of the force no longer take their offices subject to being summarily dismissed, demoted, or suspended by the chief. The act is designed to abolish those measures. In that regard, the powers of the chief are limited, but he does retain all of the powers not circumscribed. . . . The retained powers of the chief are those which do not defeat the purpose or object of the act.”
*30State ex rel. Kuszewski v. Board Of F. & P. Comm., 22 Wis.2d at 24-25.
The foregoing contract provisions providing for the reservation of the right to transfer in the Chief of Police; the express acknowledgment in the contract of the Chief’s statutory responsibilities under Chapter 586 and the prohibition against the impairment of these responsibilities, when examined cumulatively, give the Chief of Police unrestricted discretion over transfers within the department.
In Milwaukee Police Asso. v. Milwaukee, supra, this court was asked to determine whether the arbitrator exceeded his authority when devising an award which required that “when and if an opening for a police officer develops” the grievant be granted a transfer. The court held that the arbitrator exceeded his power and contract authority because the arbitrator “. . . ignored numerous provisions in the agreement giving deference to the authority and responsibilities placed upon the chief of police . . .” by statute and the collective bargaining agreement. In addition, the court found that the arbitrator by requiring that when an opening arose, a transfer be granted, in effect added to the labor agreement a provision compelling employee transfers. Milwaukee Police Asso. v. Milwaukee, 92 Wis.2d at 158-159.
That case, however, was not dealing with the further question presented here. The collective bargaining agreement vests authority in the arbitrator to decide grievances arising over discipline which are not subject to review by the Police and Fire Commission. Unless questions concerning the propriety of transfers are in the exclusive control of the Chief of Police, it would appear that the Chief of Police’s power over transfers is limited by the arbitrator’s power to resolve disciplinary grievances concerning transfers. This is not a case in which the Chief of Police has acted to limit his statutory dis*31cretion over the supervision of the department by contract; the contract at issue here expressly recognizes the reservation of power in the Chief. See, Glendale Prof. Policemen’s Asso. v. Glendale, 83 Wis.2d 90, 107, 264 N.W.2d 594 (1978).
The arbitrator in this case incorporated in his decision a portion of an earlier arbitration decision under the same collective bargaining agreement which ruled that transfers are subject to the arbitration process. The test adopted by the arbitrator to determine whether a transfer was “improper” was whether the transfer was made unfairly or showed favoritism. The problem with this ruling is that nowhere in the contract can be found a provision allowing the arbitrator to determine whether a transfer was “unfair” or showed “favoritism.” The contract states that the City and the Chief “shall have the right to transfer employes ... in a manner most advantageous to the City.” (emphasis added). There is nothing in the agreement to limit this right to only those transfers which the arbitrator deems fair and' impartial. The arbitrator ignored the numerous contract provisions detailed above. The arbitrator, in essence, added a provision to the agreement which did not otherwise exist and thereby exceeded the powers vested in him by the contract.
The arbitrator only considered whether the transfer was unfair because he felt a higher burden was imposed upon the grievant to show unfairness in a transfer than need be demonstrated to show the transfer was a disciplinary measure for which no cause had been shown. The arbitrator in assessing his power under the contract stated that “since the contract provides that discipline shall be for cause, it would follow that the arbitrator has the authority to determine whether there was cause for the discipline, absent any other limitations in the Agreement.” What the arbitrator failed to consider was that *32the contract had granted the City and Chief of Police the management right to transfer employes and the agreement also recognized the rights retained in the Chief of Police by statute. The contract provision governing discipline is subject to the management rights retained. The arbitrator therefore, in effect, removed the right to transfer from that group of management rights vested in the City and the Chief of Police and placed the right to transfer under the disciplinary provisions of the contract. This is a modification of the contract clearly in excess of the arbitrator’s authority under the agreement.
We therefore hold that the arbitrator exceeded his contract authority in ordering that the grievant be transferred back to acting detective status.
By the Court. — The decision of the court of appeals which affirmed the order of the circuit court is affirmed.
The court of appeals decision filed on October 27, 1978, is unpublished.
There is no position known as “acting detective” in the recognition clause of the contract.
Although the issue as framed by the arbitrator as well as the actual award is phrased in terms of “assignment” rather than “transfer,” the arbitrator based his determination as to arbitrability on whether the grievant was transferred. In his decision he stated:
“Having concluded a transfer is involved in the instant matter, 'and having previously concluded that transfers are covered by the terms of the Contract between the parties, it would follow that the issue in the case at bar properly falls under the jurisdiction of the Arbitrator.”
Because the defendants-petitioners do not raise the issue of whether the City has waived its right to contest the arbitrability of the dispute, we proceed to the merits of whether the arbitrator had the authority to hear the grievance of Marvin Lund.
United Steelworkers Of America v. American Mfg. Co., 363 U.S. 564 (1960) ; United Steelworkers Of America v. Warrior & Gulf Navigation Co., 363 U.S. 574 (1960) ; United Steelworkers Of America v. Enterprise Wheel & Car Corp., 363 U.S. 593 (1960).