When you create a new model, one default element named "Scorecard", which is of the element type Top Element, is created at the top of the element hierarchy. An element of type Top Element is the element highest in the element hierarchy and therefore is the compilation element of all other elements in the scorecard.
You can use a top element to draw together data from the elements below them (the compilation elements and sub elements). For instance, the top element can be defined to compile all elements in that scorecard. This element would provide you with an overview of your scorecard's overall performance.
Default Period of the Top Element