Before scheduling a protest hearing, the county assessor shall notify the director and assure that the assigned property appraisal officer board member will be made available. The director may assign a property appraisal officer to act as a member of more than one county valuation protests board. He also may establish and publish schedules for hearings on protests in the various counties to make the most efficient use of assigned property appraisal officers and assure the expeditious determination of protests.