Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Figure 9-15: Usage example of item flows in internal block diagrams Source OMG Systems Modeling Language (SysML) 1.6 Copyright information About Object Management Group copyright in text extracts quoted from OMG specifications for educational purposes Snippet kind INFO UML keywords InformationFlow SysML keywords ItemFlow Previous snippet Full quote Item flows in internal block diagrams specify flows local to a block. Next snippet For example, in Figure 9-15 the connector to the output of the water heater has an item flow indicating distilled water is flowing, even though the out flow property of the water heater indicates it produces water. Related snippets Related snippets (backlinks) For example, in Figure 9-15 the connector to the output of the water heater has an item flow indicating distilled water is flowing, even though the out flow property of the water heater indicates it produces water. The water heater is fed from a water distiller in this particular usage, so the modeler knows the output will always be distilled water, rather than other kinds of water. The radiator on the left requires distilled water, and its connection to the water heater is compatible because the item flow narrows the items to distilled water. Item flows can also be more general than the actual flow, as shown by the connector on the right. The water distiller produces distilled water, but the item flow is for any kind of fluid. The connection to the water heater is compatible because it accepts any kind of water, including distilled. The item flow does not require the heater to accept any kind of fluid, because the source of flow is still producing water, regardless of the generality of the item flow. Item flows specify the things that flow between blocks and/or parts and across associations or connectors. Whereas flow properties specify what “can” flow in or out of a block, item flows specify what “does” flow between blocks and/or parts in a particular usage context. This important distinction enables blocks to be interconnected in different ways depending on its usage context. For example, tanks might include a flow property that can accept fluid as an input. In a particular use of tanks, “gasoline” flows across a connector into a tank, and in another use of tanks, “water” flows across a connector into a tank. The item flow in each case specifies what “does” flow on the connector in the particular usage (e.g., gas, water) and the flow property specifies what can flow (e.g., fluid). This enables type matching between the item flows and between flow properties... Visit also Visit also (backlinks) Flags
