Mich. Comp. Laws § 289.3123

Sec. 3123. (1) A compliance evaluation of each food service establishment shall be performed by the director at least once every 6 months or as required by a statewide department approved risk-based schedule. Risk-based schedules shall be developed in consultation with local health departments. (2) A food service establishment which operates for 9 or fewer months each year shall be inspected at least once during the period of operation by the director or as prescribed in the department's risk-based schedule.