Notwithstanding other provisions of law, state agencies may increase or decrease individual employee salaries based upon performance. Such increase or decrease shall be determined by the agency. Performance increases shall not place an employee’s salary above the maximum of the grade or executive compensation level. Performance decreases may not place an employee’s salary below the minimum of the grade or executive compensation level. Performance decreases shall be based on the results of an EPMS evaluation. Employees assessed salary decreases may seek redress through the state employees’ grievance system.