This part of the Operations Tab displays the precedence graph of your product. Each box on the graph represents an operation and each arrow a precedence between two operations.

   There are multiple drawing possibilities for this graph accessible via the menu "Operation-View Preferences". You can also use the two zoom buttons to shrink/expand the graph.

    To select an operation, simply click on it. The properties panel will become enabled in the bottom of the window. You can also select multiple operations by holding the shift key while clicking on it.

    To move an operation, simply drag it where you want in the view.