The appointing authority shall promulgate rules and regulations implementing RCW
28B.50.850 through
28B.50.869 and shall provide for the award of faculty tenure following a probationary period not to exceed nine consecutive college quarters, excluding summer quarter and approved leaves of absence: PROVIDED, That tenure may be awarded at any time as may be determined by the appointing authority after it has given reasonable consideration to the recommendations of the review committee. Upon formal recommendation of the review committee and with the written consent of the probationary faculty member, the appointing authority may extend its probationary period for one, two, or three quarters, excluding summer quarter, beyond the maximum probationary period established herein. No such extension shall be made, however, unless the review committee's recommendation is based on its belief that the probationary faculty member needs additional time to complete satisfactorily a professional improvement plan already in progress and in the committee's further belief that the probationary faculty member will complete the plan satisfactorily. At the conclusion of any such extension, the appointing authority may award tenure unless the probationary faculty member has, in the judgment of the committee, failed to complete the professional improvement plan satisfactorily.