SysML Glossary
Presented by Tonex Training
SysML/ MBSE / Systems Engineering Glossary
This glossary page features a list of the important terminology what are frequently used in requirements management, systems engineering and V&V (validation and verification). It also includes terms used in model-based systems engineering (MBSE).
Presented by Tonex Training
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Activities : Activity modeling emphasizes the inputs, outputs, sequences, and conditions for co-ordinating other behaviors. It provides a flexible link to blocks owning those behaviors.
Activity diagram : In UML 2.1, all behaviors including activities are classes, and their instances are executions. SysML clarifies the semantics of composition association between activities, and between activities and the type of object nodes in the activities, and defines consistency rules between these diagrams and activity diagrams
Allocation : Allocation is the term used by systems engineers to denote the organized cross-association (mapping) of elements within the various structures or hierarchies of a user model.
Allocation tables: Allocation relationships may be depicted in tables. A separate row is provided for each «allocate» dependency. “from” is the client of the «allocate» dependency, and “to” is the supplier. Both ElementType and ElementName for client and supplier appear in this table.
Architecture : The SysML language reuses and extends many of the packages from UML.
Attributes : Stakeholders, purpose, concerns, languages, methods
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Binding Connector : A Binding Connector is a connector which specifies that the properties at both ends of the connector have equal values. It can only be used by a DataType or ValueType, and it must hold equal values for both ends.
Block : A Block is a modular unit that describes the structure of a system or element. It may include both structural and behavior features, such as properties and operations
Block definition diagram : A block definition diagram is based on the UML class diagram, with restrictions and extensions as defined by SysML.
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Comments : Comments can be associated with any model element and are quite useful as an informal means of documenting the model. The comment is not included in the model repository.
Complex number : A complex number consists of a real part defined by a real number, and an imaginary part defined by a real number multiplied by the square root of -1.
Compliance : Compliance with SysML requires that the subset of UML required for SysML is implemented, and the extensions to the UML subset required for SysML are implemented.
Connector Property : ConnectorProperty may only be applied to properties of classes stereotyped by Block.
Constraints : SysML defines a special form of compartment, with the label "constraints," which may contain one or more constraints.
Constructs : The static and structural constructs used in SysML structure diagrams, including the package diagram, block definition diagram, internal block diagram, and parametric diagram.
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Design principles : The static and structural constructs used in SysML structure diagrams, including the package diagram, block definition diagram, internal block diagram, and parametric diagram.
Diagrams : SysML diagrams contain diagram elements (mostly nodes connected by paths) that represent model elements in the SysML model, such as activities, blocks, and associations.
Dimension: Dimension is defined as a stereotype of InstanceSpecification, but it uses this metaclass only to define supporting elements for ValueType definitions.
Distributed Property : DistributedProperty is a stereotype of Property used to apply a probability distribution to the values of the property.
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Elements : The diagram elements tables are intended to include all of the diagrammatic constructs used in SysML.
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Feature support statements : These statements clarify which language features are not satisfied in terms of language units and/or individual packages, as well as for less precisely defined dimensions such as semantic variation points
FlowPort : A FlowPorts is an interaction point through which input and/or output of items such as data, material, or energy may flow. The notation of flow port is a square on the boundary of the owning block or its usage
FlowProperty : A FlowProperty signifies a single flow element that can flow to/from a block. A flow property's values are either received from or transmitted to an external block.
FlowSpecification : A FlowSpecification specifies inputs and outputs as a set of flow properties. It has a “flowProperties” compartment that lists the flow properties.
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Icons : A comment note box may contain stereotype keywords or icons even though Comment is not a named element.
IEEE : SysML has extended the concept of view and viewpoint from UML to be consistent with the IEEE 1471 standard.
Internal block diagram: An internal block diagram is based on the UML composite structure diagram, with restrictions and extensions as defined by SysML.
Interoperability : SysML inherits the XMI interchange capability from UML. SysML is also intended to be supported by the ISO 10303-233 data interchange standard to support interoperability among other engineering tools.
Item Flow: An ItemFlow describes the flow of items across a connector or an association. The notation of an item flow is a black arrowhead on the connector or association.
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Layering: SysML packages are specified as an extension layer to the UML metamodel.
Library models: The SysML user model is created by instantiating the metaclasses and applying the stereotypes specified in the SysML profile and subclassing the model elements in the SysML model library.
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Metaclasses: The SysML profile specifies the extensions to UML. It references the UML4SysML package, thus importing all the metaclasses into SysML that are either reused as-is from UML or extended in SysML.
Model library: The SysML user model is created by instantiating the metaclasses and applying the stereotypes specified in the SysML profile and subclassing the model elements in the SysML model library.
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Namespace compartment: A compartment with the label “namespace” may appear as part of a block definition to show blocks that are defined in the namespace of a containing block.
NestedConnectorEnd stereotype: The NestedConnectorEnd stereotype of UML ConnectorEnd extends a UML ConnectorEnd so that the connected property may be identified by a multi-level path of accessible properties from the block that owns the connector.
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Package diagrams : The package diagram and the callout notation are two mechanisms that SysML provides for adding flexibility to represent a broad range of diagram elements on diagrams. The package diagram can be used quite flexibly to organize the model in packages and views.
Parametric diagrams: The parametric diagram is a new SysML diagram type that describes the constraints among the properties associated with blocks. This diagram is used to integrate behavior and structure models with engineering analysis models
ParticipantProperty: The keyword «participant» before a property name indicates the property is stereotyped by. The types of participant properties can be elided if desired.
Problem description: A Problem documents a deficiency, limitation, or failure of one or more model elements to satisfy a requirement or need, or other undesired outcome
Profiles package : The Profiles package contains mechanisms that allow metaclasses from existing metamodels to be extended to adapt them for different purposes. This includes the ability to tailor the UML metamodel for different domains
Property: A property can represent a role or usage in the context of its enclosing block. A property has a type that supplies its definition
Property path name : A property name shown inside or outside the property box may take the form of a multilevel name. This form of name references a nested property accessible through a sequence of intermediate properties from a referencing context.
PropertySpecificType: The PropertySpecificType stereotype is automatically applied to a classifier created by the notation for a property-specific type for a property belonging to a SysML Block or ValueType.
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Rationale: A Rationale documents the justification for decisions and the requirements, design, and other decisions. A Rationale can be attached to any model element including relationships.
Real: A Real value type represents the mathematical concept of a real number. A Real value type may be used to type values that hold continuous quantities, without committing a specific representation.
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Sequence diagram: The sequence diagram describes the flow of control between actors and systems (blocks) or between parts of a system.
Standard Port: A standard port specifies the services the owning block provides (offers) to its environment as well as the services that the owning block expects (requires) of its environment.
State machine diagram : The high level states or modes of the HybridSUV including the events that trigger changes of state are illustrated in the state machine diagram.
State machines: The StateMachine package defines a set of concepts that can be used for modeling discrete behavior through finite state transition systems
stereotype keyword : A comment note box may contain stereotype keywords or icons even though Comment is not a named element. UML specifies placement of a stereotype keyword relative to the name of the element
Structural Constructs: The static and structural constructs used in SysML structure diagrams, including the package diagram, block definition diagram, internal block diagram, and parametric diagram. Structure.
Syntax: The diagram elements are referred to as the concrete syntax.
SysML: SysML reuses a subset of UML 2 and provides additional extensions needed to address requirements in the UML for Systems Engineering RFP.
SysML diagram: SysML diagrams contain diagram elements (mostly nodes connected by paths) that represent model elements in the SysML model, such as activities, blocks, and associations.
SysML ValueType : A SysML Block defines a collection of features to describe a system or other element of interest. A SysML ValueType defines values that may be used within a model.
Systems engineering: Systems engineering is an inter-disciplinary field of engineering that focusses on how to design, manage and optimize complex engineering systems over their life cycles.
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UML: Unified Modeling Language.
Unit : A Unit is a quantity in terms of which the magnitudes of other quantities that have the same dimension can be stated. A unit often relies on precise and reproducible ways to measure the unit.
Use case diagram: The use case diagram describes the usage of a system (subject) by its actors (environment) to achieve a goal, that is realized by the subject providing a set of services to selected actors.
Use cases: The use cases “Accelerate,” “Steer,” and “Brake” are modeled using the include relationship. Include is a DirectedRelationship between two use cases, implying that the behavior of the included use case is inserted into the behavior of the including use case.
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ValueType: A ValueType defines types of values that may be used to express information about a system, but cannot be identified as the target of any reference.
Viewpoint description: A Viewpoint is a specification of the conventions and rules for constructing and using a view for the purpose of addressing a set of stakeholder concerns.
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XML Metadata Interchange (XMI): The OMG XML Metadata Interchange (XMI) 2.1 standard specifies an XML-based interchange format for any language modeled using MOF.
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