(concurring in part, dissenting in part). The present action is a class action suit brought by the Detroit Federation of Teachers for an injunction or mandamus to compel compliance, by the Detroit School Board with § 569 of the School Code, MCLA 340.569; MSA 15.3569 which provides in pertinent part that:
"The board of every district shall hire and contract with such duly qualified teachers as may be required. All contracts with teachers shall be in writing * * * .”
Two issues are posed in the case. First, do the teachers bringing this action have a right to a written contract under § 569 of the School Code? We conclude that these teachers do in fact have such a right.
Second, do these teachers, or any segment of them have a right to a probationary contract? We conclude that all teachers who meet the requirements for a probationary teacher and who carry the responsibility associated with a probationary teacher have a right to a probationary contract, and their individual rights as established under these guidelines may be established by the trial court.
I — Facts
On February 8, 1972, the Detroit School Board adopted a resolution stating that henceforth "Teaching assignments and all other assignments of new or returning personnel shall be made as *230ESRP [i.e., emergency substitute in a regular position] assignments and not as regular or probationary assignments”.
As a result, many full-time teachers for the 1972-73 academic year were labeled ESRPs, were denied a written contract, and were subject to termination on 48 hours notice. In contrast, probationary teachers had in the past received a written contract which by its terms required sixty days notice before termination.* 1
On January 2, 1973, DFT filed this class action suit in Wayne County Circuit Court seeking mandamus or an injunction to compel the Detroit Board’s compliance with § 569 of the School Code, through the issuance of written contracts to teachers who had been designated ESRPs.
Judge Gilmore issued a mandamus order on January 24, 1973 to compel compliance with § 569 as follows:
"IT IS ORDERED that the defendant, the Board of Education of the School District of the City of Detroit, its agents, servants, employees, successors, assigns, attorneys and all persons acting in concert with them and all persons to whom knowledge of these premises may *231come, be and they are hereby ordered to comply with said Section 569 of the School Code of 1955, as amended, and, specifically, to enter into individual, written contracts as attached hereto (being the defendant’s standard probationary contract form), with all certiñcated teachers (whether or not heretofore denominated 'emergency substitutes in regular positions’ (ESRPs), and not already on continuing, annual or probationary contracts) who, on or about January 15, 1973, were assigned to teach in a regular position (i.e., other than as a temporary replacement for another teacher on illness or temporary disability leave), for the school year 1972-73, effective for each teacher the first date of his assignment; provided that nothing herein contained shall be in derogation of the rights, of any teacher on account of tenure to an annual or continuing contract for the 1972-73 school year; and further provided that in the event a dispute arises as to inclusion of any teacher in said class, the Court reserves jurisdiction to determine as necessary the identity and individual effective dates of persons in the said class; provided that the rights of such persons shall retrospectively attach as otherwise provided under the foregoing provisions of this Order.
"The Court further reserves jurisdiction to render further and ancillary orders in implementation of the foregoing.” (Emphasis added.)
Thus, under the trial court order, all teachers who had been designated ESRPs obtained the right to a written probationary contract unless they served as a temporary replacement for another teacher on illness or temporary disability leave.
On November 29, 1973, the Court of Appeals, in an opinion written by Chief Judge Lesinski, affirmed the trial court’s order.
On June 27, 1974, we granted leave to appeal.
II — Discussion
The threshold question in the instant case is *232whether the complaining teachers, though labeled ESRPs as a budget-cutting effort by the Detroit board, are entitled to a written contract under § 569 of the School Code.
Clearly, these teachers have such a right to a written contract under the clear language of § 569. The statute mandates that each school board enter into a written contract with such "duly qualified teachers as may be required”.
The teachers here are "duly qualified”, for Judge Gilmore’s order is applicable only to teachers who are certified. Moreover, they are "required” once the Detroit board has determined to hire them to fulfill full teaching responsibilities. Therefore, by the terms of the statute, these teachers are entitled to written contracts.
The Detroit board argues, however, that even if the teachers encompassed in Judge Gilmore’s order are entitled to written contracts, they are not all entitled to probationary contracts specifically.
My Brother Levin basically concurs with this view, stating that § 569 does not impose a legal duty to offer a teacher a particular kind of contract. He would leave the form of written contract to be granted to the complaining teachers to the agreement of the parties, and notes that the collective bargaining agreement between DFT and the Detroit board provides a procedure for resolving disputes involving the work situation. CBA, Art XXI, § A.
While I agree with my Brother Levin in concluding that § 569 of the School Code alone does not mandate any particular form of contract, this is not the end of our inquiry.
Where the complaining teachers meet all the requirements for probationary teachers established by the board itself and carry the responsibilities of *233a probationary teacher, those teachers are entitled to receive probationary contracts and the courts can properly order such action. Such is the case not because § 569 by itself requires. probationary contracts for these teachers, but because pursuant thereto the collective bargaining agreement between the parties so requires.
Appellant Detroit School Board itself acknowledges that:
" * * * a collective bargaining agreement, unlike a commercial contract, consists not only of written contractual language but also the past practice of the parties.” (Appellant’s Brief, p 36.)
See also John Wiley & Sons, Inc v Livingston, 376 US 543, 549-550; 84 S Ct 909; 11 L Ed 2d 898 (1964); United States Steel Workers of America v Warrior & Gulf Navigation Co, 363 US 574, 578-579; 80 S Ct 1347; 4 L Ed 2d 1409 (1960).
Certain requirements or criteria for probationary teachers have been established through past practice, as appellant’s admissions indicate:
1) The teachers must be on the Detroit board eligibility list;2
2) The teacher must be certified in the subject matter which he or she teaches;
*2343) The teacher must go through a screening process.
These criteria have thus become part of the collective bargaining agreement, and teachers who have met the requirements and who carry the responsibility of a probationary teacher are entitled under the agreement to a probationary contract.
This conclusion is further supported by the fact that the Detroit board has acknowledged the right of 306 teachers formerly labeled ESRPs to probationary contracts because they met the requirements and carried the responsibilities of a probationary teacher. As to those teachers, the Detroit board no longer disputes the propriety of Judge Gilmore’s order.
There remain, however, some 995 teachers whose probationary contracts are in dispute. An analysis of the record indicates that these teachers, though all labeled ESRPs, held three types of positions or responsibilities:
1) Approximately 565 ESRPs were assigned to substitute for tenured or probationary teachers who take a leave of absence from their Detroit board funded regular positions to work in a Federal or state funded position;
2) Approximately 265 ESRPs served in positions funded by the Federal or state government;
3) Approximately 175 ESRPs served as relief teachers for tenured or probationary teachers who are making use of the one hour of preparation time allowed them each day.
A number of the teachers in these three groups were improperly granted probationary contracts under the trial court order. Some of them did not meet the requirements or criteria of a probationary teacher as discussed above. For example, ap*235proximately 330 ESRPs were not on the Detroit board’s eligibility list.
Moreover, it is arguable that teachers in the first category did not hold the kind of position associated with the status of probationary teachers. These teachers in effect, it is argued, substituted for tenured or probationary teachers who were working in specially funded programs. Their position could be of indefinite duration, for the continuance of Federal or state funds for these special programs can be uncertain, and the tenured and probationary teachers who taught in these programs had been promised that if funds terminated or if they simply desired to end their participation in the program, their regular positions would be made available to them.
For similar reasons it is argued that members of the second group of teachers are likewise not entitled to a probationary contract.
Members of the third group of teachers, who are otherwise qualified, however, are clearly entitled to a probationary contract, for the following reasons. First, these positions are funded in the same manner as tenured and probationary teachers, not being dependent on special Federal and state grants.
Second, these positions are not temporary in nature or uncertain in duration. Under the collective bargaining agreement, tenured and probationary teachers are allowed an hour of preparation time each day, and so long as this agreement remains in effect, there will be a need for these relief teachers to teach.
Third, unless these teachers are granted probationary status, and made subject to continuing evaluation, as probationary teachers, they may be unfairly deprived of tenure.
*236Under the teachers tenure act, MCLA 38.71 et seq.; MSA 15.1971 et seq., qualified teachers are entitled to tenure upon reappointment after a two-year probationary period. MCLA 38.81; MSA 15.1981.3 During this period, the work of the probationary teacher is evaluated. MCLA 38.83; MSA 15.1983. If these relief teachers are not granted probationary contracts and are not evaluated as probationary teachers, they may work a full day each school day for the two-year period of time without earning the opportunity to gain tenure.
Thus, teachers who are in this class, who meet the requirements for probationary teachers noted above, are entitled to a probationary contract, and the trial court and Court of Appeals properly enforced this right.
There remains only the question of the method to be used to resolve further questions raised here between the teachers and the Detroit board regarding the first two classes.
The nature of the contract to be granted ESRPs not clearly entitled to probationary contracts is a matter for negotiation between the parties under their bargaining agreement.
However, the rights of individual teachers to probationary contracts under the guidelines of this opinion is a matter best resolved by the continuing jurisdiction of the trial court.
While the collective bargaining agreement between the parties provides for a grievance procedure, this procedure was intended to be "supplementary to * * * remedies afforded to any teacher by law”. Art XXI, § F. The teachers here have a proper remedy at law which is properly enforced by the trial court.
*237Ill — Conclusion
We hold that the teachers here bringing suit are entitled to written contracts under § 569 of the School Code, and that those teachers who meet the requirements for probationary teachers established by the Detroit board and who fill the responsibilities of a probationary teacher as described above, are entitled to probationary contracts.
This case is remanded to the circuit court for a declaration of rights under this opinion.
Other consequences of being designated an ESRP rather than a probationary teacher included the following:
1. Probationary teachers with less than two years seniority generally will not be transferred under the collective bargaining agreement, CBA, Art XII, § G at 23.
2. Probationary teachers are entitled to immediate life insurance benefits, while ESRPs are not entitled to life insurance benefits unless they have worked in this classification for two years immediately preceding their death or retirement. CBA, Art XVI, § B(6) at 42.
3. Probationary teachers are allowed credit on the salary schedule for up to eight years of outside teaching experience. CBA, Appendix, Art 2 at 59.
4. A probationary teacher has greater priority upon returning from leave. CBA, Art XV, § G(l) at 41.
5. Two years satisfactory teaching as a probationary teacher entitle the teacher to tenure, MCLA 38.81; MSA 15.1981.
The eligibility list requirements are:
"1. A bachelor’s degree from a college or university accredited, at the time the degree was granted, hy the North Central Association of Colleges and Secondary Schools, or an equivalent agency.
"2. A Michigan State Provisional, Permanent, or Life Certificate.
"3. A satisfactory college or university record with adequate and up-to-date preparation in the field of specialization.
"4. A satisfactory record of supervised or directed teaching or other teaching experience.
"5. Status as a native or naturalized citizen of the United States, or an individual who has filed his declaration of intention to become a citizen.”
MCLA 38.82; MSA 15.1982 allows a third year of probation in some circumstances.