OMG SysML Portal

Behavior The activation/deactivation of one or more functions. Note: This describes how a system interacts with its environment. Reactive behavior includes the stimulus and response.

		Behavior allocation				The allocation of functions and/or states to systems, and the allocation of inputs and outputs to system ports.
		Boolean				Refer to UML specification
		Category				A partitioning of elements based on a classification.
		Complex number				A number which can includes a real and imaginary part.
		Component				A constituent part of an element or system that contributes to the properties and behaviors of the whole (emergent). Note: A leaf component does not have constituent parts.
		Composite function				A function which is decomposed into lower level functions.
		Composite state				A state which includes nested states.
		Concurrent state				A state which is active at the same time as another state that is part of the same composite state.
		Condition				An expression with a discrete output, which is true as long as the expression evaluates true, and is false otherwise.
		Connecting component				A specialized component or system, whose primary function is to connect the outputs from one system to the inputs of another system via its ports.  Note: This may be a wire, network, or mechanical coupler that has properties and behaviors, which may transform the inputs and outputs.
		Connection				Identification of which ports connect to one another.
		Connection path				Multiple connections that may represent a single logical connection.
		Continuous time model				A model which is based on properities that vary continuously with time.
		Control input				An input that activates or deactivates a function.
		Control operator				A specialized function that provides logic to transform input events and conditions to discrete values that are supplied as control inputs to functions.
		Data				A component of information.
		Data type				Refe to UML specification
		Decomposition				A description of a whole in terms of its component parts.
		Dependency				A relationship where a change to one entity results in a change to the other.
		Deployment				A allocation of one component to another that is often associated with the utilization of resources across the distributed nodes of a system.
		Design				The process of transforming requirements to an implementation.
		Design constraint				A requirement that one or more components of a system must satisfy. Note: This term is sometimes used to refer to a constraint on the design process versus the system.
		Diagram interchange				The ability to exchange notational information on a diagram, including the layout of the diagram.
		Discrete time model				A model which is based on properities that vary discretely with time.
		Domain				A scope that encompasses a set of entities and relationships that may be addressed by the model.
		Effectiveness measure				A criterion for system optimization that is critcial to the success of the mission. Note: The criterion are often used to support trade studies to select among alternatives,as well as to optimize a given design.
		EIA 632				A process standard for Engineering a System.
		Element				Anything of interest to the modeler, which is uniquely identifiable and can be characterized by a set of properties.
		Enabling system				Any system which may be needed to support another system throughout its life cycle, and typically includes the development, production, deployment, support, and disposal systems.
		Enumerated value				Refer to UML specification
		Environment				A collection of systems and elements that interact either directly or indirectly with the system of interest.
		Event				A noteworthy occurrence that occurs at the instant of time when a specified expression evaluates true.
		Execution				The state of the system or model when it is running. For a model, this implies that model computation is occuring.
		Expression				Refer to UML specification
		Facility				A physical infrastructure that supports use of equipment and other resources.
		Failure				An inability to satsify a requirement.
		Fork				A control operator which enables all of its outputs, when the input is evaluated true.
		Function				A transformation of inputs to outputs that may include the creation, monitoring, modification or destruction of elements, or a null transformation.
		Function port				A binding of an input to the arguments of a function.
		Function time-line				A representation of the interval of time that one or more functions and/or states are active and inactive.
		Functional requirement				A function a system must perform.
		Generalization				The factoring of common features to characterize a more general concept.
		Geometric model				A model of the geometric relationships associated with one or more elements.
		Hardware				A component of a system that has geometric contstraints.
		IDEF0				Air Force Standard for process modeling.
		Input/Output				An element that is subject to a transformation by a function.
		Instance				A unique model element in a set that iis defined by the general features of its classifier.
		Integer				A whole number
		Interaction				Emergent behavior that results from two or more dependent behaviors Note: A system or component interacts with other components its environment, to yield an emergent system behavior from the individual component behaviors .
		Interface				The inputs, outputs, ports, connections, connecting components (i.e. harness), and associated information that support one or more interactions between systems. Note: The UML definition of interface also includes the operations that must be performed in response to the inputs or invocations.
		Interface requirement				An interface a system must support.
		ISO 15288				A process standard for system life cycle processes.
		Issue (technical)				A potential problem, that requires resolution.
		Iteration loop				A specialized loop where the loop repeats a specified number of times.
		Join				A control operator which enables its control output, when all of its inputs are evaluated true.
		Leaf function				A function which is not further decomposed.
		Loop				A control operator which initiates one or more loop functions when the input is evaluated true, and is repeated as long as the loop conditions are evaluated true.
		Manual procedure				A set of operations that provide instructions for a user to perform.
		Mean				The expected value associated with a probability distirbution.
		Merge				A control operator which enables its output, when any of its inputs are evaluated true.
		Mission				The operational context and purpose that the system is intended to support.
		Model (graphical, visual)				A representation of something of interest that includes notation and semantics.
		Model element				A construct that is used to build a model.
		Model interchange				The ability to exchange model information.
		Model view				A subset of model elements and associated relationships, that are of use to the modeler for a particular purpose and context.
		Natural object				An element that is not engineered, and may be part of a system or environment.
		Need				A desired requirement of a stakeholder.
		Nested state				A state which is enabled by its composite state.
		Node				A component of a system that provides resources to support execution.
		Notation				The graphical depiction of a model construct.
		Operational requirement				A requirement which is associated with the operation of a system, and typically includes a combination of functional, interfrace, and performance requirements.
		Parametric model				An analysis model which defines a set of dependent or logically grouped parametric relationships.
		Parametric relationship				A dependency between properties, such that a change to the value of one property impacts the value of the other property.
		Performance property				A measure of the transformation or response of a function or behavior (i.e response time, etc.).
		Performance requirement				A performance property a system must satsify.
		Physical property				A physical characteristic of a system or element (i.e. weight, color).
		Physical requirement				A physical property a system must satsify.
		Port				The part of a system or component that provides access between a system’s behaviors and properties, and its environment.  Note: this is sometimes referred to as an interaction point.
		Probability distribution				A mathematical function which defines the likelihood of a paritcular set of outcomes.
		Probe				A component that monitors the values associated with one or more parameters (i.e. properties).
		Problem				A deficiency, limitation, or failure to satisfy a requirement or need, or other undesired outcome. Note: A problem may be associated with the behavior, structure, and/or properties of a system or element at any level of the hierarchy (i.e. system of system level, down to a component/part level).
		Problem cause				The relationship between a problem and its source problems (i.e. cause). Note: This cause affect relationship is often represented in fishbone diagrams, fault trees, etc..
		Process				A set of inter-related functions and their corresponding inputs and outputs, which are activated and deactivated by their control inputs.
		Property				A quantifiable characteristic.
		Property association				The assignment of a property to a model element or set of model elements.
		Property attribute				
		Property value				Unique state of a property.
		Real number				A number which can have any value from negative infinity to infinity.
		Replicate function				A function which represents the same transformation, but is implemented by separate resources.
		Requirement				The capability, behavior, structure, and/or properties that a system, component, or element must satisfy. Note: This is used to establish a contract between the customer (or stakeholder) and implementer.
		Requirement allocation				The assignment of a requirement to an element, component, or system.
		Requirement attribute				An attrirbue fo a requirement, which may include its criticality or weighting, level of uncertainty, verification status, etc.
		Requirement traceability				The relationship between a source requirement and the derived requirements needed to satisfy the source requirement.
		Requirement type				A category of requirement. Note: This includes functional, interface, performance, etc.
		Requirement verification				A comparison between a requirement and the verification results that is intended to satisfy the requirement.
		Resource				Any element that is needed for the execution of a function.
		Role				Refer to System role
		Scalable				A measure of the extent to which the modeling langauge (or methodology, etc), can be adapted to an increase in scope and/or complexity.
		Selection				A control operator which represents a test that enables an output based on the values/conditions of the input.
		Semantics				The meaning of a model element. Note: a precise meaning should be able to be expressed mathematically.
		Sequential state				A state which can only be active when the other sequential states are not active.
		Simple state				A state that does not have nested states.
		Software				A component of a system that specifies instructions which are executed by a computer.
		Source requirement				The requirement which is the basis for deriving one or more other requirements.
		Spatial representation				A geometrical relationship among elements.
		Specialization				A classification of an entity (e.g., element, system, function, requirement, ...), which specifies the common features of the more general element, and unique features of the specific element.
		Specialized requirement				A requirement that is not explicitly addressed by the default requirement types. Note: This may include safety, reliabillity, maittianability, producibility, usability, security, etc.
		Specialty engineering				A general term for engineering disciplines associated with some specific aspects of a system, suchas reliability or safety engineering.
		Specification				One or more requirements for a system, component or element.
		Stakeholder				Individuals, groups, and/or institutions which may be impacted by the system throughout its life cycle, including acquisition, development, production, deployment, operations, support, and disposal.
		State (finite)				A condition of a system or element, as defined by some of its properties, which can enable system behaviors and/or structure to occur. Note: The enabled behavior may include no actions, such as associated with a wait state. Also, the condition that defines the state may be dependent on one or more previous states.
		State based behavior				Behavior which is described by states and transitions between states.
		Storage device				A component of a system that is used to store a system store. Note: this may include memory device, a battery, or a tank..
		Store requirement				An element a system must store.
		String				A value represented by alphanumeric characters.
		Structure				The relationships between the components that contribute to the properties of the whole, and enable them to interact (inter-relate).
		Subsystem				A logical or physical partitioning of a system.
		System				An element, with structure, that exhibits observable properties and behaviors.
		System (component) boundary				The set of all ports, which connect the system (component) to its environment.
		System context				A depiction of the inputs and outputs between a system and its environment.
		System hierarchy				A decomposition of a system and its components.
		System interconnection				The connection between systems and between components.
		System role				A subset of its behaviors, properties, and structure. Note: The subset may be associated with specific interactions.
		System store				An input/output element that persists over time, which may be depletable or non-depletable. Note: Non-depletable stores may include data store in computer memory, and depletable stores may include energy in a battery, or fluid in a tank.. Physical stores obey the conservation laws (only take out what is put in).  A non-depletable store, such as a data store, is not constrained by the conservation laws. The system store should be differentiated from the storage device, which stores the element.
		Test case				The input stimulus, expected output, and associated test criteria which verify that the system satisfies its requirements or needs.
		Test scenario				A scenario which replicates the behavior of the environment that interacts with the system under test.
		Text based requirement				One or more requirements specified in text.
		Thread				A process with no concurrent functions, and represents a single path of execution.
		Time property				A property of the model that represents a local or global time, which other properties may depend on. . Note: The property can support continuous or discrete-time models. This variable should not be confused with the measured or computed time that an actual system uses, which depends on a number of implementation specific factors related to clocks, synchronization, etc.
		Topology				A graph of nodes and arcs.
		Trade-off study				An evaluation of alternatives based on a set of evaluation criteria.
		Transition				Response to events/conditions, which triggers a behavior.
		Triggering input				An input which is required for a function to be activated.
		UML				A visual modeling language used for representing systems
		User				An individual or group of individuals that use a system.
		Validation				The process for demonstrating that a system or its requirements satisfy the stakeholder needs.
		Variance				A measure of the distribution about the mean of a probability distribution. Refer to the mathematical definition associated with a probability distribution.
		Vector				A data type, which specifies a magnitude and direction.
		Verification				The process for demonstrating a system satisfies its requirements.
		Verification procedure				The functions needed to support execution of a test case. Note. This may include generating an input stimulus and monitoring an output response.