Threat Models are defined through the description of the system in scope through the identification of its elements. Those elements are represented by Entities, Flows, and Trust Boundaries. The main approach adopted by Threats Manager Studio (TMS) to describe Threat Models, is through diagrams. Each diagram describes a scenario or a part of the system. As such, it is only normal to have the same elements included in multiple diagrams.
TMS allows to assign the same objects to multiple diagrams, through the Existing Object Palette.
This palette is available in the Diagram tool and allows listing the objects defined in the Threat Model but missing from the current diagram. Therefore, including an object missing from the diagram is only a matter of selecting the Existing Object Palette, select the type of object you are searching for (External Interactor, Process, Data Store, or Trust Boundary), and then dragging it and dropping in the desired position, in the diagram.
Tips & Tricks
Flows are not available in the Existing Object Palette. This is because TMS automatically recognizes that a Flow already exist, and applies all its properties as you draw it.