(1) Bibliography is provided by the book supply department to the ordering group.

The group obtained the books to be ordered from all units.

(3) according to

The purpose is to generate the book ordering text.

(4) Feedback ordering information (including quantity, quantity, etc.). ) to the book supplier.

) notify the unsubscribed books to order books.

(6) The system will automatically double-check the books ordered and feed back the results.

Try to draw as required.

The data flow diagram of the topic and convert it into a software structure diagram.