Icon class icon_class far fa-sticky-note icon_class_computed far fa-sticky-note Note kind MODELLING OPTION TIP Policy level INFORMATIVE Specification keywords SysML-1.6 SysML-1.7 UML keywords Signal InformationFlow InformationFlow::conveyed SysMLv1.x keywords Block ValueType ItemFlow ItemFlow::itemProperty Keywords Systems Modeling Language SysML flow signal flow Webel Best Practice Discussion under: Webel Best Practice: SysML: Whether you use a Block, ValueType, or Signal to represent something that flows (and can be applied to an ItemFlow) depends on what you want to achieve. If you want to indicate something structured with value properties with Units use a Block. Relates to Overview of flowing quantities and Port types with flows Overview of ValueTypes and Units Related notes [MODELLING, TIP]{SUGGESTED} SysML-1.6/1.7: You can introduce a custom (user-defined) stereotype keyword «item» to indicate Properties that are to be used as "packets" for ItemFlows on Connectors. (SysMLv2 will have a formal way of treating such items/packets.) [MODELLING, OPTION, TIP]{INFORMATIVE} SysML: Whether you use a Block, ValueType, or Signal to represent something that flows (and can be applied to an ItemFlow) depends on what you want to achieve. If you want to indicate something structured with value properties with Units use a Block. [PROPOSAL]{SUGGESTED} WISHLIST: Webel has suggested that future SysML should support the display of Classifier-level :features in compartments on a rectangular itemProperty symbol on an ItemFlow on a Connector in an IBD. Related notes (backlinks) [ASSERTION, MODELLING, TIP]{STRICT} SysML+SysPhS: Flows: If you intend to use a Classifier to type the itemProperty of an ItemFlow on a Connector for a physical interaction you MUST use a Block (not a ValueType or Signal) so your can extend ConservedQuantityKind. Related snippets (extracts) [SysML-1.6] Item flows on connectors shall be compatible with flow properties of the blocks usages at each end of the connector, if any. The direction of the item flow shall be compatible with the direction of flow specified by the flow properties. [SysML-1.6] FlowProperty::1_restricted_types A FlowProperty shall be typed by a ValueType, Block, or Signal. Visit also Visit also (backlinks) Flags Book traversal links for SysML: Flows: If you intend to use a Classifier to type the itemProperty of an ItemFlow on a Connector use a ValueType or Block rather than a Signal, otherwise you'll get probably-unwanted signal receptions on the owning context Block. Previous Up Next
