Event Handlers Tab
Use the Event Handlers tab of SSIS Designer to build a control flow in an Integration Services package. An event handler runs in response to an event raised by the package or by a task or container in the package.
Create the control flow by dragging graphical objects that represent SSIS tasks and containers from the Toolbox to the design surface of the Event Handlers tab, and then connecting the objects by using precedence constraints to define the sequence in which they run.
Additionally, to add annotations, right-click the design surface, and then on the menu, click Add Annotation.