The grievant, the representatives of the grievant, the exclusive representative (if the grievant is a member of the bargaining unit represented by the exclusive representative), and the representatives of the Department are entitled to be present at the hearing. The Board may, after considering the views of the parties and any other individuals connected with the grievance, decide that a hearing should be open to others. Testimony at a hearing shall be given under oath, which any Board member or individual designated by the Board shall have authority to administer.

Each party (including an exclusive representative appearing in the proceedings) shall be entitled to examine and cross-examine witnesses at the hearing or by deposition and to serve interrogatories upon another party and have such interrogatories answered by the other party unless the Board finds such interrogatory irrelevant, immaterial, or unduly repetitive. Upon request of the Board, or upon a request of the grievant deemed relevant and material by the Board, an agency shall promptly make available at the hearing or by deposition any witness under its control, supervision, or responsibility, except that if the Board determines that the presence of such witness at the hearing is required for just resolution of the grievance, then the witness shall be made available at the hearing, with necessary costs and travel expenses paid by the Department.

During any hearing held by the Board, any oral or documentary evidence may be received, but the Board shall exclude any irrelevant, immaterial, or unduly repetitious evidence, as determined under section 556 of title 5.

A verbatim transcript shall be made of any hearing and shall be part of the record of proceedings.

In those grievances in which the Board does not hold a hearing, the Board shall afford to each party the opportunity to review and to supplement, by written submissions, the record of proceedings prior to the decision by the Board. The decision of the Board shall be based exclusively on the record of proceedings.

The Board may act by or through panels or individual members designated by the Chairperson, except that hearings within the continental United States shall be held by panels of at least three members unless the parties agree otherwise. References in this subchapter to the Board shall be considered to be references to a panel or member of the Board where appropriate. All members of the Board shall act as impartial individuals in considering grievances.

If the Board determines that the Department is considering the involuntary separation of the grievant (other than an involuntary separation for cause under section 4010(a) of this title), disciplinary action against the grievant, or recovery from the grievant of alleged overpayment of salary, expenses, or allowances, which is related to a grievance pending before the Board and that such action should be suspended, the Department shall suspend such action until the date which is one year after such determination or until the Board has ruled upon the grievance, whichever comes first. The Board shall extend the one-year limitation under the preceding sentence and the Department shall continue to suspend such action, if the Board determines that the agency or the Board is responsible for the delay in the resolution of the grievance. The Board may also extend the 1-year limit if it determines that the delay is due to the complexity of the case, the unavailability of witnesses or to circumstances beyond the control of the agency, the Board or the grievant. Notwithstanding such suspension of action, the head of the agency concerned or a chief of mission or principal officer may exclude the grievant from official premises or from the performance of specified functions when such exclusion is determined in writing to be essential to the functioning of the post or office to which the grievant is assigned.

The Board may reconsider any decision upon presentation of newly discovered or previously unavailable material evidence.