Cal. PUC § 1705

At the time fixed for any hearing before the commission or a commissioner, or the time to which the hearing has been continued, the complainant and the corporation or person complained of, and such corporations or persons as the commission allows to intervene, shall be entitled to be heard and to introduce evidence. The commission shall issue process to enforce the attendance of all necessary witnesses. After the conclusion of the hearing, the commission shall make and file its order, containing its decision. Except for decisions filed after hearings held under Section 1702.1, the decision shall contain, separately stated, findings of fact and conclusions of law by the commission on all issues material to the order or decision. A copy of such order, certified under the seal of the commission, shall be served upon the corporation or person complained of, or his or its attorney. The order shall, of its own force, take effect and become operative 20 days after the service thereof except as otherwise provided by the commission, and shall continue in force either for a period designated in it or until changed or abrogated by the commission. If the commission believes that an order cannot be complied with within 20 days, it may prescribe such additional time as in its judgment is reasonably necessary to comply with the order, and may on application and for good cause shown, extend the time for compliance fixed in its order. Decisions rendered in response to complaints filed and processed pursuant to Section 1702.1 shall not be considered as precedent or binding on the commission or the courts of this state.