If a past practice exists, a municipality may not possess the management right to assign a new, probationary worker to any work shift, in order to reduce overtime opportunities for other workers. In February 2012, the Town of Stratford hired Heather Admans as a full-time dispatcher. Although initially assigned to work 8 a.m. to 4 p.m., Admans agreed to work several different work shifts in February. On Feb. 23, 2012, Admans worked 4 p.m. to midnight, and another worker, Annabel Diaz, was not offered callback overtime. Diaz filed a grievance and argued that Admans should not have been assigned to the 4 p.m. work shift on Feb. 23, 2012. The union maintained that a past practice exists that once a probationary worker indicates a preference for a shift, and that shift becomes the worker's regular shift, the worker remains in that shift for several months. The municipality argued that management possesses the right to assign probationary workers to vacant shifts, to reduce callback overtime. The municipality claimed that once Admans was assigned to work the 4 p.m. shift on February 23, there was no vacancy in that work shift for that day and no opportunity for callback overtime. Section 6.2 of the collective bargaining agreement provides, "No employee shall be allowed to change shift or regular days off if such change would create a known order back or callback." Arbitrators voted, 2-1, to sustain the grievance, because past practice established that Section 6.2 applies to probationary workers. "[O]nce a probationary employee is initially assigned to or indicates a preference for a shift," wrote arbitrators, "then that shift becomes their regular shift and they remain in that shift until the next bid process." Arbitrators ordered the municipality to make Diaz whole for lost callback overtime that she would have earned, if Admans had not worked the 4 p.m. work shift on February 23. Christopher Hodgson represented the municipality, and Owen Sullivan represented the union.