Exercise: monthly publication usage

(source: Mark Olson)

A large task for computer manufacturers is to keep track of their publications: product specification sheets, marketing brochures, user manuals, and so on. One major manufacturer had developed a spreadsheet to record the monthly usage of each publication (that is, how many copies of the publication were distributed each month). Then they decided to export the spreadsheet into a database. The export program naturally converted each column of the spreadsheet into a database table attribute, so the result looked something like this:

Monthly publications use class diagram

• Revise the class diagram to correct any problems that you find in this design. Then draw the relation scheme for your corrected model.