Traceability is the means of capturing implementation and dependency relationships in the model. For example, a business process will require some system functionality (use cases) to implement the process functions. Enterprise Architect lets you capture this information using Realisation links. Use Analysis diagrams associated with processes, use cases, classes & etc to capture the realisation relationships. The following diagrams illustrates how an implementation diagram looks and how it is used:

Implementation details are usually placed in Analysis diagrams under the principal model element (in the picture below that is the Login use case.

The diagram below indicates that the Login use case implments (or Realises) the Logon to the Website formal requirements and is in turn implemented by the Business Logic, ASP pages components and Login Web Page.

Once these relationships are made, they can be queried using the Implmentation and Dependency reports available from the Project Browser context menu:

Details on all implmentation links in the selected package tree are displayed (and a report can be generated to save this information):

Dependency reports are similar but capture the reverse end of the link - that is, what model elements depend on an element for realisation.