In the first three parts of this series, we showed how elements of the central SysML model for a consumer appliance could be connected via Syndeia to elements in PLM (PTC Windchill), requirements (Jama Software) and simulation (MATLAB Simulink, The MathWorks). If we add internal connections within the SysML model to connect structure and requirements, the result is a single unified graph extending over all four tools. In this part, we will demonstrate how Syndeia (Intercax) allows the user to explore and visualize that graph.

SysML Structure-Requirements Relationships

SysML supports many different kinds of internal relationships, but we shall focus on one, the Satisfy dependency that indicates a model element, e.g. a structure component, that is judged to satisfy a system requirement. Figure 1, a SysML Requirement diagram, shows a partial, but representative list of requirements for our washing machine and the structural elements that satisfy them.

Figure 1 SysML Structure-Requirement relationships

Some requirements, such as CE Certification, can only be satisfied by the complete system, while others are satisfied by subsystems or individual components.

Other SysML internal (or intra-model) relationships are not shown in this diagram, including the hierarchical (containment) relationship between requirements, and the composition (part property) relationships between structural components. In combination, they create a single unified SysML model.

Visualizing the Total System Model

Syndeia offers a variety of visualizations for exploring this network of inter-model and intra-model connections. Figure 2 shows a chord plot of all the inter-model connections Syndeia manages between Windchill, Simulink, Jama and the SysML model.

Figure 2  Syndeia global visualization showing inter-model connections between SysML, Windchill, Simulink and Jama

The small circles on the perimeter are model elements, color-coded to the tool or repository in which they reside. The chord lines spanning the circle represent inter-model connections between individual elements in different tools. The legend on the right shows a total of 66 connections involving 105 model elements.

While the artifacts and connections are searchable and filterable, this type of display is probably most useful as a quick snapshot of what tools are connected and how densely. Our interest in other cases is on individual elements and chains of connections. These extended chains may include both inter-model and intra-model connections and can be explored in various local visualizations initiated from a single model element.

Figure 3 Syndeia local visualization initiated from Mechanical_Subsystem block

In Figure 3, we began such a visualization from a SysML block, Mechanical_Subsystem, and displayed its nearest neighbors. Many of these are the parts of that subsystem as SysML blocks, connected by part property relationships, but the Mechanical_Subsystem block is also connected to a Windchill part and a Simulink block. Two of the nearest neighbors, Vibration Sensor on the left and Agitator on the right, were further expanded and showed Windchill and Simulink connections of their own. Vibration_Sensor is also connected to a SysML requirement, which, if further expanded, would be connected to a Jama requirement.  By further expansion, more and more of the Total System Model graph is revealed.

The power of the Model-Based Engineering approach begins to emerge. By creating a roadmap of system data, the TSM

  • Provides continuous traceability, even as the system evolves
  • Facilitates navigation across the system model, showing where your data lives
  • Supports metrics and model validation, e.g. completeness.

Next Steps

Two important deficits in our modeling may be evident at this stage,

  • We have ignored some important areas in system development, such as software and project management, and
  • Our visualizations are not the focused queries we would like to ask our model.

In the final piece of this series, Part 5, we will show how Syndeia can help address these deficits.

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Dirk Zwemer

Dirk Zwemer

Dr. Dirk Zwemer (dirk.zwemer@intercax.com) is President of Intercax LLC (Atlanta, GA), a supplier of MBE engineering software platforms like Syndeia and ParaMagic. He is an active teacher and consultant in the field and holds Level 4 Model Builder-Advanced certification as an OMG System Modeling Professional.