(1) When, in a case of adjudication, a majority of the officials of the agency who are to render the decision have not heard the case or read the record, the decision, if adverse to a party other than the agency, shall not be made until a proposal for decision is served upon the parties and an opportunity is afforded to each party adversely affected to file exceptions and present briefs and oral argument to the officials who are to render the decision. The proposal for decision shall contain a statement of the reasons therefor and of each issue of fact or law necessary thereto, prepared by the person who conducted the hearing.
(2) In every case of adjudication, a final decision or order shall be in writing or stated in the record.
(3) A final decision shall include findings of fact and conclusions of law, separately stated. Findings of fact, if set forth in statutory language, shall be accompanied by a concise and explicit statement of the underlying facts supporting the findings. If, in accordance with agency rules, a party submitted proposed findings of fact, the decision shall include a ruling upon each proposed finding.
(4) Parties shall be served either personally or by mail with a copy of any decision or order.