Mass. Gen. Laws ch. 150E § 8
The parties may include in any written agreement a grievance procedure culminating in final and binding arbitration to be invoked in the event of any dispute concerning the interpretation or application of such written agreement. In the absence of such grievance procedure, binding arbitration may be ordered by the commission upon the request of either party; provided that any such grievance procedure shall, wherever applicable, be exclusive and shall supercede any otherwise applicable grievance procedure provided by law; and further provided that binding arbitration hereunder shall be enforceable under the provisions of chapter one hundred and fifty C and shall, where such arbitration is elected by the employee as the method of grievance resolution, be the exclusive procedure for resolving any such grievance involving suspension, dismissal, removal or termination notwithstanding any contrary provisions of sections thirty-nine and forty-one to forty-five, inclusive, of chapter thirty-one, section sixteen of chapter thirty-two, or sections forty-two through forty-three A, inclusive, of chapter seventy-one. Where binding arbitration is provided under the terms of a collective bargaining agreement as a means of resolving grievances concerning job abolition, demotion, promotion, layoff, recall, or appointment and where an employee elects such binding arbitration as the method of resolution under said collective bargaining agreement, such binding arbitration shall be the exclusive procedure for resolving any such grievance, notwithstanding any contrary provisions of sections thirty-seven, thirty-eight, forty-two to forty-three A, inclusive, and section fifty-nine B of chapter seventy-one.
Mass. Gen. Laws ch. 150E, § 8