Abstract: A system for creating queries for complex data structures includes a database populated with data relating to a manufacturing process and a graphical user interface accessed via a computer. The graphical user interface includes a tree domain and a query area, the tree domain including a tree representation of the data populating the database, wherein the tree representation includes graphical representations of attributes and/or structural-elements relating to the manufacturing process and populating the database. A mechanism is provided for dragging and dropping the graphical representations from the tree domain to the query area where the graphical representations are converted to a query based upon operators linking the graphical representations dragged and dropped from the tree domain.