The stakeholder’s concern is about the dynamic sequence of events (“signal handover”) and the interaction between system parts (ground stations). A Sequence Diagram is specifically designed to model this kind of time-ordered interaction, showing messages passed between lifelines (representing the blocks/actors) to capture the flow of events, making it the most direct and clear choice.

A state invariant is a constraint placed on a state that must hold true whenever the system is in that state. It is the correct construct to formally specify the condition “joint_position == home” (or similar) for the ‘Calibrate’ state. Entry/do activities are behaviors that execute, not conditions that must be true, and a change event triggers a transition.

The «deriveReqt» relationship indicates a deductive relationship. It means the target requirement (engine horsepower) was derived from the source requirement (vehicle speed) through analysis, calculation, or rationale. It documents the thought process behind the decomposition, not verification status (verify), structural hierarchy (containment), or dependency (satisfy).

To show the flow of a specific item (electrical power) between parts in an IBD, you use an item flow. It is depicted as a black arrowhead on a connector (which is based on an association block from the BDD). This specifies not just that the parts are connected, but what exactly flows across that connection. A binding connector is for equality, and dependency/information flows are more abstract and not typically used for physical flows in IBDs.

In a Parametric Diagram, you bind value properties of blocks (the model’s variables) to the parameters of constraint properties (the equations). This is done using binding connectors (`=`), which assert equality between the connected elements. This setup allows analysis tools to execute the constraint, solving for unknowns by using the bound values from the system model.

An «extend» relationship is used for optional behavior. An «include» relationship is for mandatory, common behavior that is factored out. If ‘Log Maintenance Activity’ is a mandatory step within both ‘Update Software’ and ‘Replace Hardware’, then it should be an «include» of each of those specific use cases, not of the high-level ‘Maintain System’. Including it at the top level would incorrectly imply it’s part of every maintenance scenario. The scenario describes a common, required behavior across specific cases.

A transition guard is a Boolean expression attached to a transition in a State Machine Diagram. It prevents the transition from being taken unless the condition is true. To prohibit the ‘gear down’ command when weight is on wheels, you would place a guard like `[weight_on_wheels == false]` on the transition leading to the ‘gear down’ state. This embeds the safety rule directly into the executable behavior logic. While constraints and traces document the rule, a guard actively controls the modeled behavior.

Generalization in SysML means the child block (RedundantSensorModule) inherits all features (properties, operations, relationships) from the parent block (SensorModule). This includes the composition relationships that define its parts. Therefore, RedundantSensorModule inherently has parts SensorA and SensorB. As a specialization, it can then add more parts (e.g., ‘SensorC’) or modify inherited ones, but it starts with the parent’s structure.

Swimlanes (formally called Activity Partitions) are vertical or horizontal lanes on an Activity Diagram used to group actions based on a common characteristic, most often the entity (e.g., a block, actor) responsible for performing those actions. This visually answers the question “who does what?” directly within the behavioral flow. Allocation is a more abstract relationship, and call behaviors show hierarchy but not responsibility per se.

The stakeholder’s concern is about the dynamic sequence of events (“signal handover”) and the interaction between system parts (ground stations). A Sequence Diagram is specifically designed to model this kind of time-ordered interaction, showing messages passed between lifelines (representing the blocks/actors) to capture the flow of events, making it the most direct and clear choice.0