Mich. Comp. Laws § 125.82

Sec. 12. All actions of local legislative bodies under the provisions of this act shall be by ordinance or resolution and such ordinance or resolution shall be subject to the same provisions regarding procedure and executive veto as are applicable to other ordinances or resolutions of the legislative body. Any provision in this or any other act or in the charter of any municipality to the contrary notwithstanding, any action of local legislative bodies relating to the approval or modification of a development plan heretofore taken under the provisions of this act by resolution and all actions subsequent thereto dependent on such earlier actions are validated. Any development plan heretofore approved by resolution may thereafter be modified by resolution.