From time to time as it deems necessary, the board may establish additional classes and divide, combine, alter, or abolish existing classes. In establishing, altering, or abolishing classes, the board shall consider the recommendations of the Department of Human Resources. When those actions are taken the board shall determine in each instance whether positions affected are to be reallocated to another class or classes after taking into account the duties and responsibilities, qualifications, performance standards, and other related criteria before and after the change, and shall determine the status of the probationary and permanent employees affected.