Mich. Comp. Laws § 24.227

Sec. 27. (1) A guideline adopted after the effective date of this section is not valid unless processed in substantial compliance with sections 24, 25, and 26. However, inadvertent failure to give notice to any person as required by section 24 does not invalidate a guideline which was otherwise processed in substantial compliance with sections 24, 25, and 26. (2) A proceeding to contest a guideline on the grounds of noncompliance with sections 24, 25, and 26 shall be commenced within 2 years after the effective date of the guideline.