Each customer has a name, address, login name and password. Each customized book matches various book components. A book component has a content, price and author. Each author has a name that uniquely determines the author within this database. Book components also have specifications.
Specifications are boolean expressions based on elementary specifications.
One now looks for phrases that suggest relationships from one class to another. For each relationship, I have noted the phrase in the original requirements that justifies the relationship. Operation operatesOn Expression Find attributes Words that modify nouns are used to determine the attributes that each class should have. As with the relationships, each attribute is traced back to the requirements. Operations were also traced back to the requirements.