In case that the production order is known (and people do not have to search for it through other selections) you could create a selection field / list box of the orders and set the properties of this object to 'Always One Selected Value' (Tab General). Please note that you should select one order first in this selection field/list box in order to enable this option.
An other way is to add a calculation condition in the objects itself. (chart properties - calculation condition), fi "count (distinct Order) = 1". This way the object will only be calculated when 1 order is selected, and an error message will be dislayed when more orders are selected.