The Employer unilaterally created an afternoon shift that had not been negotiated with the Union and assigned an employee to it. All shifts in the agreement had traditionally been negotiated. The Arbitrator agreed with the Union that the Employer could not create a non negotiated shift (except for abnormal or emergency circumstances) and allowed the grievance.
The take away is that when parties negotiate specific shifts and hours for employees those must be respected and cannot be unilaterally changed pursuant to “management rights”.
The case can be read here.