The use of the EntitySpecification/Entity pattern was considered to support the requirements.  However, this would proliferate the number of EntitySpecifications and Entities from an implementation perspective.  In this example, there would have to be a separate instance of EntitySpecification for each movie and a separate instance of an Entity for each chosen movie.  Using the generalized CharacteristicSpecification/Characteristic model eliminates this.  In this example there could be a single instance of an EntitySpecification that represents Pay Per View and a single instance of and Entity that represents a Pay Per View subscription.<br/>Enhancements to the Characteristic Model<br/><ul>
<li>Add two new entities to the characteristic model</li><li>Add associations to ProductOfferingPrice and ComponentProductPrice.</li></ul>
Also, catalogs of movies can be created by adding a composite CharacteristicSpecification named Video Catalog and associating the Movie Title composite with it.  Since this is dependent on the “use” of the values, a recursive association on EntitySpecCharValueUse is required.  A similar association and association class is also added to EntitySpecCharUse as shown in Figure Ch.06 – Updated Characteristic Use Entities.<br/>