Integrated master plan An event-driven plan that documents the significant accomplishments necessary to complete the work and ties each accomplishment to a key program event. Integrated master schedule An integrated and networked schedule of tasks required to complete a defined work effort or scope of work. Milestone hierarchy A hierarchy of specific project milestones. Organizational breakdown structure A structure that defines how an entity is organized. Resource breakdown structure A structure that defines the resource classifications necessary to complete a project. Work breakdown structure A structure that defines the work that must be accomplished to complete a project. Mutually defined Mutually agreed upon hierarchical structure type.