Although certain agency decisions are not subject to bargaining, they may have a substantial impact on bargaining unit employees. As such, procedures for implementing these agency actions and arrangements for employees adversely affected are bargainable, even if the decisions themselves are not subject to bargaining because they involve the exercise of rights reserved to management. Moreover, the impact and implementation, or procedures and arrangements bargaining obligation arises only as the result of a management initiative -- i.e., of a proposed action that has a substantial impact on the conditions of employment of bargaining unit employees. The difficulty arises because the distinction between procedure and substance is not always clear.