The Union sought to amend Certification No. 55-70 to add the title Director of Motor Equipment Maintenance (Sanitation), contending that changed circumstances mandate that the Board re-evaluate the title and add it to the bargaining unit. The City argued that the title should remain excluded from collective bargaining as managerial. The Board held that the title is eligible for collective bargaining with the exception of the Deputy Commissioner for Support Services position that the parties agree is managerial.