(concurring specially)-
I agree that the applicability of the arbitration clause to the board’s proposed action is “reasonably debatable,” so that the matter should go to arbitration, including the timeliness of the grievance.
*485In my view the board’s proposed action does not increase the hours of employment; the hours remain the same. It is only the duties to be performed in those hours that change. Petitioner claims that, notwithstanding the board’s policy giving the superintendent the right to assign the daily teaching load, there exists a past practice of only four student contact hours in the basic day. This presents an issue as to the “common law of the shop,” an issue which draws its “essence” from the collective bargaining agreement and which, therefore, is for the arbitrator to decide. In the Matter of Arbitration Between Ramsey County vs. American Federation of State, County and Municipal Employees, Council No. 91, Local 8,-N.W.2d-(Minn.1981), filed September 4, 1981.
Under the master contract and pursuant to Minn.Stat. § 179.66, subd. 1 (1980), the school board’s inherent managerial rights include “direction * * * of personnel.” If a change in the teaching load is a managerial prerogative, as it seems to me it is, it nevertheless has economic aspects affecting teachers’ compensation, which aspects are terms and condition of employment and, as such, would be arbitrable. Cf. International Union of Operating Engineers, Local No. 49 v. City of Minneapolis, 305 Minn. 364, 373, 233 N.W.2d 748 (1975) (giving of competitive exams is a managerial right included in “selection * * * of personnel,” but the fairness of the exam is a negotiable term and condition of employment).