Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content ExampleBlock in a Block Definition Diagram (BDD) 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 Property Port ports compartment SysML keywords Block block property Keywords systems engineering Model-Based Systems Engineering SysML Systems Modeling Language Previous snippet A block can include properties to specify its values, parts, and references to other blocks. Full quote Ports are a special class of property used to specify allowable types of interactions between blocks ... Next snippet Constraint Properties are a special class of property used to constrain other properties of blocks... Related snippets Blocks are modular units of system description. Blocks provide a general-purpose capability to model systems as trees of modular components. The specific kinds of components, the kinds of connections between them, and the way these elements combine to define the total system can all be selected according to the goals of a particular system model. Parts in these systems may interact by many different means, such as software operations, discrete state transitions, flows of inputs and outputs, or continuous interactions. The Block Definition Diagram in SysML defines features of blocks and relationships between blocks such as associations, generalizations, and dependencies. It captures the definition of blocks in terms of properties and operations, and relationships such as a system hierarchy or a system classification tree The Internal Block Diagram in SysML captures the internal structure of a block in terms of properties and connectors between properties. Related snippets (backlinks) Various notations for properties are available to distinguish these specialized kinds of properties on an internal block diagram. A property can represent a role or usage in the context of its enclosing block. A property has a type that supplies its definition. A part belonging to a block, for example, may be typed by another block. The part defines a local usage of its defining block within the specific context to which the part belongs. For example, a block that represents the definition of a wheel can be used in different ways. The front wheel and rear wheel can represent different usages of the same wheel definition. SysML also allows each usage to define context-specific values and constraints associated with the individual usage, such as 25 psi for the front tires and 30 psi for the rear tires. Constraint properties are further defined in Clause 10. A port is another category of property, as further defined in Section 9. A property typed by a Block that does not have composite aggregation is classified as a reference property. A property typed by a SysML Block that has composite aggregation is classified as a part property, except for the special case of a constraint property ... A property typed by a SysML ValueType is classified as a value property, and always has composite aggregation. Part, reference, value, and constraint properties may be shown in block definition compartments with the labels "parts," "references," "values," and "constraints" respectively. Properties of any type may be shown in a "properties" compartment or in additional compartments with user-defined labels. Visit also Visit also (backlinks) Flags