The Instance component is a table that contains data associated with business objects such as Orders and Invoices. Instances of these objects are uniquely identified by a number. The Instance component belongs in an application database. An Invoice is a member of the Class BusinessObject. Invoice number 1234 is an Instance of an Invoice. The BusinessObject Instance contains summary or heading data. There is usually a date, some descriptive text and totals rolled up from any associated Detail components. Detail components contain all of the relationships to the Organizations, People, Activities, LocationsProperties, Items and Codes associated with the Invoice.

Now I'm getting ahead of myself here, but I'm going to show you a couple of data models that ilustrates this component. I will get into detail of the notation in the next section, but here's what this thing looks like.

An instance of a BusinessObject may have a Class component as a parent when the DBMS does not have an automatic serial numbering feature or when summary totals of all of the Instances are maintained. In this case, the Class BusinessObject contains the NextInstance and summaries, and here's what this puppy looks like.