Artifact: Design Model
 Design Model |
The design model is an object model describing the realization of use cases, and serves as an abstraction of the implementation model and its source code. The design model is used as essential input to activities in implementation and test. |
| UML representation: | Model, stereotyped as «design model». |
| Worker: | Architect |
| Reports: | Design-Model Survey |
| More information: | Guidelines: Design Model |
Purpose 
The following people use the design model:
- The use-case designer to see what classes and objects are available at a specific time.
- The designer to get a comprehensive picture of the design.
- The architect to get a comprehensive picture of the software architecture.
- The tester to plan tests and follow up test results.
- The manager to plan and follow up the design work.
- The people looking at the next evolution cycle to get a full picture of the design.
Properties
Property Name |
Brief Description |
UML Representation |
| Introduction | A textual description that serves as a brief introduction to the model. | Tagged value, of type "short text". |
| Design Packages | The packages in the model, representing a hierarchy. | Owned via the association "represents", or recursively via the aggregation "owns". |
| Classes | The classes in the model, owned by the packages. | Owned recursively via the aggregation "owns". |
| Relationships | The relationships in the model, owned by the packages. | - " - |
| Use-Case Realizations | The use-case realizations in the model, owned by the packages. | - " - |
| Diagrams | The diagrams in the model, owned by the packages. | - " - |
| Logical View | The logical view of the model, which is an architectural view showing the significant packages, classes, and use-case realizations. | Elements and diagrams in the view are owned recursively via the aggregation "owns". |
| Process View | The process view of the model, which is an architectural view showing the processes (active classes). | - " - |
| Deployment View | The deployment view of the model, which is an architectural view showing the physical network configurations (nodes). | - " - |
Timing
The design model primarily sets the architecture, but is also used as a vehicle for analysis during the elaboration phase. It is then refined by detailed design decisions during the construction phase. The design model is continuously kept consistent with the use-case model and the implementation model.
Responsibility
An architect is responsible for the integrity of the design model, ensuring that
- The design model as a whole is correct, consistent, and readable. The design model is correct when it realizes the functionality described in the use-case model, and only this behavior.
- The architecture in the design model fulfills its purpose, including the logical, process, and deployment view. These views are collected in a separate artifact, see Artifact: Software Architecture Document.
Note that the architect is not responsible for the packages, classes, relationships, use-case realizations, and the diagrams themselves; instead, these are under the corresponding designers and use-case designer's responsibilities.
