In any contested case the department may direct that the proceedings or any part of the proceedings be heard by a hearing examiner to be appointed by the department. Proceedings before a hearing examiner shall be according to this chapter, other applicable laws and the rules of the department. Whenever a contested case, or any part of a contested case, is heard by a hearing examiner, the hearing examiner shall make a proposal for decision in writing, which shall include findings of fact and conclusions of law made by the hearing examiner. The proposal for decision shall be served on all parties of record, and each party who would be adversely affected by the proposed decision shall be given an opportunity to file exceptions and present argument in writing to the department itself. Before the department enters a final order in such cases, the members thereof shall personally consider the entire record, or the portion of the record cited by the parties, and shall make its decision in the form and manner prescribed by this chapter for decisions in contested cases.