Package relationships are also added to the model. The type of relationship is a dependency relationship, shown as a dashed arrow to the dependent package, as shown in Figure 6-10. If package A is dependent on package B this implies that one or more classes in package A initiates communication with one or more public classes in package B. Package A is referred to as the Client package and package B is referred to as the Supplier package. Package relationships are also discovered by examining the scenarios and class relationships for the system under development. As this is an iterative process, the relationships will change as analysis and design progresses.