Fast Track UML 2.0

The package merge feature of the UML allows you to merge the contents of a target package into a source package. This is useful when elements of the same name are intended to represent the same basic concepts.

The resulting merged package combines elements using generalization (see the section "Generalization" in Chapter 2) and redefinitions. The following basic rules apply:

• All existing relationships are retained intact.

• Each element within one of the packages participating in the merger gets subclassed under the original element of the same name, with the latter named package name:element name . This is necessary because the super-class elements may have brought additional properties that need to be propagated to the subclass elements.

Figure 5-7 shows an example of a package merge.

Figure 5-7: Package merge