Mich. Comp. Laws § 35.402a

Sec. 2a. In the event that it shall become necessary for reasons of public policy to reduce the number of persons in any public employment mentioned in this act, the status of persons removed from employment shall be determined on the basis of seniority of service and on the basis of quality of service as determined by the employing authority, and those having the least seniority and least quality of service shall be first removed. In the case of an employee mentioned in section 1 of this act, who was in public employment prior to and at the time of entering military service, the time spent in military service shall be added to the period of employment in case he shall return to the same or similar public employment following discharge from military service.