Structure your modeling solution
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
To use models effectively in a development project, the team members must be able to work on models of different parts of the project at the same time. This topic suggests a scheme for dividing the application into different parts that correspond to the layers in an overall layering diagram.
To start on a project or subproject quickly, it is useful to have a project template that follows the project structure that you have chosen. This topic describes how to create and use such a template.
This topic assumes that you are working on a project that is large enough to require several team members, and perhaps has several teams. The code and models of the project are stored on a source control system such as Team Foundation Server. At least some team members use Visual Studio to develop models, and other team members can view the models by using other Visual Studio versions.
To see which versions of Visual Studio support each tool and modeling feature, see Version support for architecture and modeling tools.
Solution structure
In a medium or large project, the structure of the team is based on the structure of the application. Each team uses a Visual Studio solution.
To divide an application into layers
Base the structure of your solutions on the structure of your application, such as web application, service application, or desktop application. A variety of common architectures is discussed in Application Archetypes in the Microsoft Application Architecture Guide.
Create a Visual Studio solution, which we'll call the Architecture solution. This solution will be used to create the overall design of the system. It will contain models but no code.
Add a dependency diagram to this solution. On the dependency diagram, draw the architecture you have chosen for your application. For example, the diagram might show these layers and the dependencies between them: Presentation; Business logic; and Data.
Create a separate Visual Studio solution for each layer in the Architecture dependency diagram.
These solutions will be used to develop the code of the layers.
Create models that represent the designs of the layers and the concepts that are common to all the layers. Arrange the models so that all the models can be seen from the Architecture solution, and the relevant models can be seen from each layer.
You can achieve this by using either of the following procedures. The first alternative creates a separate modeling project for each layer, and the second creates a single modeling project that is shared between the layers.
Use a separate modeling project for each layer
Create a modeling project in each layer solution.
This model will contain diagrams that describe the requirements and design of that layer. It can also contain dependency diagrams that show nested layers.
You now have a model for each layer, plus a model for the application architecture. Each model is contained in its own solution. This enables team members to work on the layers at the same time.
To the Architecture solution, add the modeling project of each layer solution. To do this, open the Architecture solution. In Solution Explorer, right-click the solution node, point to Add, and then click Existing Project. Navigate to the modeling project (.modelproj) in one layer solution.
Each model is now visible in two solutions: its "home" solution and the Architecture solution.
To the modeling project of each layer, add a dependency diagram. Start with a copy of the Architecture dependency diagram. You can delete parts that are not dependencies of the dependency diagram.
You can also add dependency diagrams that represent the detailed structure of this layer.
These diagrams are used to validate the code that is developed in this layer.
In the Architecture solution, edit the requirements and design models of all the layers by using Visual Studio.
In each layer solution, develop the code for that layer, referring to the model. If you are content to do the development without using the same computer to update the model, you can read the model and develop code by using versions of Visual Studio that cannot create models. You can also generate code from the model in these versions.
This method guarantees that no interference will be caused by developers who edit the layer models at the same time.
However, because the models are separate, it is difficult to refer to common concepts. Each model must have its own copy of the elements on which it is dependent from other layers and the architecture. The dependency diagram in each layer must be kept in sync with the Architecture dependency diagram. It is difficult to maintain synchronization when these elements change, although you could develop tools to accomplish this.
Use a separate package for each layer
In the solution for each layer, add the Architecture modeling project. In Solution Explorer, right-click the solution node, point to Add, and then click Existing Project. The single modeling project can now be accessed from every solution: the Architecture project, and the development project for each layer.
In the shared model, create a package for each layer: In Solution Explorer, select the modeling project. In UML Model Explorer, right-click the model root node, point to Add, and then click Package.
Each package will contain diagrams that describe the requirements and design of the corresponding layer.
If required, add local dependency diagrams for the internal structure of each layer.
This method allows the design elements of each layer to refer directly to those of the layers and common architecture on which it depends.
Although concurrent work on different packages can cause some conflicts, they are fairly easy to manage because the packages are stored in separate files.
Create architecture templates
In practice, you don't create all your Visual Studio solutions at the same time, but add them as the project progresses. You'll probably also use the same solution structure in future projects. To help you create new solutions quickly, you can create a solution or project template. You can capture the template in a Visual Studio Integration Extension (VSIX) so that it is easy to distribute and to install on other computers.
For example, if you frequently use solutions that have Presentation, Business, and Data layers, you can configure a template that will create new solutions that have that structure.
To create a solution template
Create the solution structure that you want to use as a starting point for future projects.
On the File menu, click Export Template as VSIX.
The Export Template as VSIX Wizard opens.
Following the instructions in the wizard, select the projects that you want to include in the template, provide a name and description for the template, and specify an output location.