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Simple Roll-Up Analysis Using Robot System with Properties

This example shows a simple roll-up analysis of a robotic system to calculate the total weight and cost of the system from its individual parts. You can perform roll-up calculations on any other system metric, for example, total power. In System Composer™, you can use the the analysis tools to iterate over elements in an architecture instance, perform calculations, and display the results in a table.

Open Model and Modify Properties Using Property Inspector

To open the model, run this command.

model = systemcomposer.openModel("RobotPhysicalArchitecture");

In the physical architecture [1] model, select the Computer component. In the Property Inspector, expand the PhysicalComponent stereotype, and view or modify the property values for the individual weight, UnitWeight, and the individual cost, UnitCost.

Robot physical architecture with a computer, robot, and power source component, each with a physical component stereotype with a specific unit weight and unit cost.

Based on the property definition on the SystemProfile profile, you can change property values of model elements in the Property Inspector. Use the Profile Editor to change property names and units for the SystemProfile profile.

Perform Simple Roll-Up Analysis To Calculate Total Cost and Total Weight

To perform a roll-up analysis, instantiate the architecture model by navigating to Modeling > Analysis Model and opening the Instantiate Architecture Model tool. An instance model is a collection of instances of architectural elements. Use this instance to calculate a total weight and total cost for the system by adding up the individual values for each model element.

In the Instantiate Architecture Model tool, select all stereotypes by selecting the SystemProfile profile check box. Specify the Analysis function by clicking the folder icon then selecting CostAndWeightRollupAnalysis.m. Then, for Iteration Order, select Bottom-up. Confirm that Strict Mode is selected, so that elements in the instantiated model get properties only if the corresponding element in the composition model has the stereotype applied.

Instantiate architecture model tool with stereotypes checked, analysis function defined, and using bottom up iteration order, in strict mode.

To view the instance, click Instantiate to create the instantiated architecture model and launch the Analysis Viewer tool. Click Analyze to execute the bottom-up analysis iterator. The iterator calls the analysis function for each element in the instantiated architecture as an input argument as the iterator works its way from the deepest level of the architecture to the top.

Analysis results in the Analysis Viewer with calculated values highlighted in yellow.

The total cost for the RobotPhysicalArchitecture architecture model is 5,100 dollars, and the total weight of the components is 55 kg. Using these metrics, systems designers can change the overall design to meet system requirements then analyze the system again. Adjust the property values in the Analysis Viewer and rerun the analysis to optimize the design to reach a solution that is acceptable both from the cost and weight perspectives.


[1] Faisandier, Alan, and Rick Adcock. “Physical Architecture.” Guide to the Systems Engineering Body of Knowledge (SEBoK) v. 2.7, released October 31, 2022.

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