If your model contains Model blocks that reference external models, test creation occurs for the top-level model, considering each referenced model in its execution context.
If multiple Model blocks reference the same model, generated tests attempt to satisfy test objectives for each instance of the referenced model in its individual context in the top-level model. If you have three Model blocks that reference a certain model, the analysis produces results for all three instances.
If you collect coverage using the generated test cases, the cumulative coverage reflects the multiple instances of the same referenced model. The simulation produces one set of coverage results for each referenced model; if you have three Model blocks that reference a certain model, the simulation produces one set of results for that referenced model.
For example, consider a top-level model with three Model blocks referencing the same model. The referenced model has three test objectives. Analyzing the top-level model produces nine test objectives. If you simulate the model with the nine test cases, the coverage results for that referenced model specify three test objectives.