Attendance of all three (3) members shall be necessary to conduct a meeting. If a member is recused from an arbitration or is unable to serve, that member shall be replaced in the manner originally appointed. Upon being called into session the board shall promptly hold hearings and shall have the power to administer oaths and to compel the attendance of witnesses and the furnishing by the parties of such information as may be necessary to a determination of the issue or issues in dispute. Both parties to the dispute shall have the opportunity to be present at the hearing, both personally and by counsel, and to present such oral and documentary evidence as the board shall deem relevant to the issue or issues in controversy.