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SECM Concept Model Definitions Snapshot (1/28/2016)

Name Documentation
Action A non-interruptible function. Note: An action represents an atomic unit of processing or work. Actions may be continuous or discrete. Discrete actions may or may not be assumed to execute in zero time.
Activation/deactivation eventAn event that occurs when a function is activated or deactivated.
Activation/deactivation requirementThe activation or deactivation that one or more functions must satsify when specified events and conditions occur.
Activation/deactivation rulesThe logic which determines when one or more functions are activated and deactivated.
Activation timeThe interval of time that a function or state is active.
ActivityOne or more related actions.
AnalysisThe process of evaluating elements, properties and associated relationships.
Analysis modelA model used to analyze the structure, behavior, and/or properties of systems and environments.
AP-233 ISO STEP Application Protocol for Systems Engineering Data Interchange Standard
Arc An association between two or more nodes.
Association Refer to UML specification
BehaviorThe 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 allocationThe allocation of functions and/or states to systems, and the allocation of inputs and outputs to system ports.
BooleanRefer to UML specification
CategoryA partitioning of elements based on a classification.
Complex numberA number which can includes a real and imaginary part.
ComponentA 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 functionA function which is decomposed into lower level functions.
Composite stateA state which includes nested states.
Concurrent stateA state which is active at the same time as another state that is part of the same composite state.
ConditionAn expression with a discrete output, which is true as long as the expression evaluates true, and is false otherwise.
Connecting componentA 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.
ConnectionIdentification of which ports connect to one another.
Connection pathMultiple connections that may represent a single logical connection.
Continuous time modelA model which is based on properities that vary continuously with time.
Control inputAn input that activates or deactivates a function.
Control operatorA specialized function that provides logic to transform input events and conditions to discrete values that are supplied as control inputs to functions.
DataA component of information.
Data typeRefer to UML specification
DecompositionA description of a whole in terms of its component parts.
DependencyA relationship where a change to one entity results in a change to the other.
DeploymentA allocation of one component to another that is often associated with the utilization of resources across the distributed nodes of a system.
DesignThe process of transforming requirements to an implementation.
Design constraintA 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 interchangeThe ability to exchange notational information on a diagram, including the layout of the diagram.
Discrete time modelA model which is based on properities that vary discretely with time.
DomainA scope that encompasses a set of entities and relationships that may be addressed by the model.
Effectiveness measureA 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 632A process standard for Engineering a System.
ElementAnything of interest to the modeler, which is uniquely identifiable and can be characterized by a set of properties.
Enabling systemAny 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 valueRefer to UML specification
EnvironmentA collection of systems and elements that interact either directly or indirectly with the system of interest.
EventA noteworthy occurrence that occurs at the instant of time when a specified expression evaluates true.
ExecutionThe state of the system or model when it is running. For a model, this implies that model computation is occuring.
ExpressionRefer to UML specification
FacilityA physical infrastructure that supports use of equipment and other resources.
FailureAn inability to satsify a requirement.
ForkA control operator which enables all of its outputs, when the input is evaluated true.
FunctionA transformation of inputs to outputs that may include the creation, monitoring, modification or destruction of elements, or a null transformation.
Function portA binding of an input to the arguments of a function.
Function time-lineA representation of the interval of time that one or more functions and/or states are active and inactive.
Functional requirementA function a system must perform.
GeneralizationThe factoring of common features to characterize a more general concept.
Geometric modelA model of the geometric relationships associated with one or more elements.
HardwareA component of a system that has geometric contstraints.
IDEF0Air Force Standard for process modeling.
Input/OutputAn element that is subject to a transformation by a function.
InstanceA unique model element in a set that iis defined by the general features of its classifier.
IntegerA whole number
InteractionEmergent 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 .
InterfaceThe 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 requirementAn interface a system must support.
ISO 15288A process standard for system life cycle processes.
Issue (technical)A potential problem, that requires resolution.
Iteration loopA specialized loop where the loop repeats a specified number of times.
JoinA control operator which enables its control output, when all of its inputs are evaluated true.
Leaf functionA function which is not further decomposed.
LoopA 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 procedureA set of operations that provide instructions for a user to perform.
MeanThe expected value associated with a probability distirbution.
MergeA control operator which enables its output, when any of its inputs are evaluated true.
MissionThe 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 elementA construct that is used to build a model.
Model interchangeThe ability to exchange model information.
Model viewA subset of model elements and associated relationships, that are of use to the modeler for a particular purpose and context.
Natural objectAn element that is not engineered, and may be part of a system or environment.
NeedA desired requirement of a stakeholder.
Nested stateA state which is enabled by its composite state.
NodeA component of a system that provides resources to support execution.
NotationThe graphical depiction of a model construct.
Operational requirementA requirement which is associated with the operation of a system, and typically includes a combination of functional, interface, and performance requirements.
Parametric modelAn analysis model which defines a set of dependent or logically grouped parametric relationships.
Parametric relationshipA dependency between properties, such that a change to the value of one property impacts the value of the other property.
Performance propertyA measure of the transformation or response of a function or behavior (i.e response time, etc).
Performance requirementA performance property a system must satsify.
Physical propertyA physical characteristic of a system or element (i.e. weight, color).
Physical requirementA physical property a system must satsify.
PortThe 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 distributionA mathematical function which defines the likelihood of a paritcular set of outcomes.
ProbeA component that monitors the values associated with one or more parameters (i.e. properties).
ProblemA 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 causeThe 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.
ProcessA set of inter-related functions and their corresponding inputs and outputs, which are activated and deactivated by their control inputs.
PropertyA quantifiable characteristic.
Property associationThe assignment of a property to a model element or set of model elements.
Property attribute
Property valueUnique state of a property.
Real numberA number which can have any value from negative infinity to infinity.
Replicate functionA function which represents the same transformation, but is implemented by separate resources.
RequirementThe 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 allocationThe assignment of a requirement to an element, component, or system.
Requirement attributeAn attrirbue fo a requirement, which may include its criticality or weighting, level of uncertainty, verification status, etc.
Requirement traceabilityThe relationship between a source requirement and the derived requirements needed to satisfy the source requirement.
Requirement typeA category of requirement. Note: This includes functional, interface, performance, etc.
Requirement verificationA comparison between a requirement and the verification results that is intended to satisfy the requirement.
ResourceAny element that is needed for the execution of a function.
ScalableA measure of the extent to which the modeling langauge (or methodology, etc), can be adapted to an increase in scope and/or complexity.
SelectionA control operator which represents a test that enables an output based on the values/conditions of the input.
SemanticsThe meaning of a model element. Note: a precise meaning should be able to be expressed mathematically.
Sequential stateA state which can only be active when the other sequential states are not active.
Simple stateA state that does not have nested states.
SoftwareA component of a system that specifies instructions which are executed by a computer.
Source requirementThe requirement which is the basis for deriving one or more other requirements.
Spatial representationA geometrical relationship among elements.
SpecializationA 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 requirementA requirement that is not explicitly addressed by the default requirement types. Note: This may include safety, reliabillity, maittianability, producibility, usability, security, etc.
Specialty engineeringA general term for engineering disciplines associated with some specific aspects of a system, suchas reliability or safety engineering.
SpecificationOne or more requirements for a system, component or element.
StakeholderIndividuals, 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 behaviorBehavior which is described by states and transitions between states.
Storage deviceA component of a system that is used to store a system store. Note: this may include memory device, a battery, or a tank.
Store requirementAn element a system must store.
StringA value represented by alphanumeric characters.
StructureThe relationships between the components that contribute to the properties of the whole, and enable them to interact (inter-relate).
SubsystemA logical or physical partitioning of a system.
SystemAn element, with structure, that exhibits observable properties and behaviors.
System (component) boundaryThe set of all ports, which connect the system (component) to its environment.
System contextA depiction of the inputs and outputs between a system and its environment.
System hierarchyA decomposition of a system and its components.
System interconnectionThe connection between systems and between components.
System roleA subset of its behaviors, properties, and structure. Note: The subset may be associated with specific interactions.
System storeAn 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 caseThe input stimulus, expected output, and associated test criteria which verify that the system satisfies its requirements or needs.
Test scenarioA scenario which replicates the behavior of the environment that interacts with the system under test.
Text based requirementOne or more requirements specified in text.
ThreadA process with no concurrent functions, and represents a single path of execution.
Time propertyA 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.
TopologyA graph of nodes and arcs.
Trade-off studyAn evaluation of alternatives based on a set of evaluation criteria.
TransitionResponse to events/conditions, which triggers a behavior.
Triggering inputAn input which is required for a function to be activated.
UserAn individual or group of individuals that use a system.
ValidationThe process for demonstrating that a system or its requirements satisfy the stakeholder needs.
VarianceA measure of the distribution about the mean of a probability distribution. Refer to the mathematical definition associated with a probability distribution.
VectorA data type, which specifies a magnitude and direction.
VerificationThe process for demonstrating a system satisfies its requirements.
Verification procedureThe functions needed to support execution of a test case. Note. This may include generating an input stimulus and monitoring an output
sysml-roadmap/secm_concept_definitions_snapshot_1_28_2016.txt · Last modified: 2016-01-29 01:15 by roncwilliamson