A risk burn down is also known as a waterfall, because it describes the shape of a waterfall as in this diagram. An area chart is used to graph the waterfall with risk level on the Y axis and time on the X axis. A dotted line at the top of the chart represents the gross risk. The area fills out to a point then steps down as it cross another dotted line which is the current risk. A green vertical line meets the edge of the area chart and the current risk line, this represent ‘now’ on the time axis. The area chart continues to move out and descend at each action point which is marked with a blue arrow and the text action plus a number for the action. 4 actions are completed. At the end of the 4th action another line is present , this is the residual risk. A target risk line is also visible below the residual line At this point the time line has stopped but the area has not reach the target line because no actions achieve that level.