How to: Add an Existing BDC Model File to a SharePoint Project
You can use Visual Studio to customize, package, and redeploy an existing Business Data Connectivity (BDC) model. To accomplish this, add the model file to any SharePoint project. BDC model files have the extension .bdcm. For more information, see Creating a Business Data Connectivity Model.
To add an existing BDC model file to a SharePoint project
In Solution Explorer, and then select the project folder.
On the Project menu, click Add Existing Item.
In the Add Existing Item dialog box, browse to the location of the Model definition file that you want to add to your project, select the file, and then click Add.
If the model does not define a Line of Business (LOB) System of type .NET assembly, the Add .NET assembly LobSystem dialog box appears. A .NET assembly LOB system enables you to write custom code and use a designer to define the metadata for the imported model.
If the dialog box appears, and you want to add a new LOB system of type .NET assembly, select Yes, name the LOB system, and the click OK.
The Business Data Connectivity Model item is added to the project.