You can add new plan by copying the existing one. First, select the plan you want to copy by clicking on it. Then click the button 
in toolbar and choose an option from the pick list as is shown in the following picture.
Plan |
It will copy only related data from Plans tab and also defined parameters from Settings tab of selected plan into a new plan. |
Plan and stocks |
It will copy related data from Plans tab and defined parameters from Settings tab and all stocks defined in Stocks tab of selected plan into a new plan. |
Plan and parts |
It will copy related data from Plans tab and defined parameters from Settings tab and all parts defined in Parts tab of selected plan into a new plan. |
Plan, stocks and parts |
It will copy all related data from selected plan into a new plan. |