Managers may exercise some discretion, subject to operational requirements. What does this mean?

Operational requirements must be based on the work itself to be performed, not on administrative or economic criteria.  Operational requirements are a question of fact to be determined in each case.   The management has discretion to grant requests and in exercising that discretion is required to act reasonably, fairly and in good faith pursuant to section 5.02 of the AJC collective agreement.