ArcLang metamodel: kinds, attributes, units

This page is generated by the compiler (arclang metamodel). A test fails when it and the compiler disagree.

Language version 4.0.0. GENERATED from src/compiler/metamodel.rs by arclang metamodel --format markdown; a golden test fails when this file and the compiler disagree. Do not edit by hand.

The metamodel is independent of Capella: it names the Arcadia metaclass each kind corresponds to, and the SysML v2 construct the exporter maps it to. Attribute values are typed; the compiler reports type violations as metamodel: warnings and the production gate turns them into blockers.

Element kinds

Operational Analysis

Actor

Human or external system interacting with the system.

Arcadia: OperationalActor
SysML v2: part def (actor)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`category`	`text`	Actor category.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).

OperationalEntity

Organization or system of the operational world.

Arcadia: Entity
SysML v2: part def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`type`	`text`	Component category (free text).
`layer`	`text`	Overrides the architectural layer label.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).

OperationalCapability

Expected ability of the operational world. May be declared inside another operational capability.

Arcadia: OperationalCapability
SysML v2: use case def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`involves`	`list<ref<Element>>`	Actors, entities, activities and processes involved.
`extends`	`list<ref<OperationalCapability>>`	Capabilities of the same level this one extends.
`includes`	`list<ref<OperationalCapability>>`	Capabilities of the same level this one includes.
`specializes`	`list<ref<OperationalCapability>>`	Capabilities of the same level this one is a special case of.

OperationalActivity

Activity performed by an entity or actor.

Arcadia: OperationalActivity
SysML v2: action def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`category`	`text`	Functional category (free text).
`inputs`	`list<text>`	Input data names.
`outputs`	`list<text>`	Output data names.
`latency`	`quantity<time>`	Execution latency; summed along functional chains by the gate.
`execution_time`	`quantity<time>`	Alias of latency.
`wcet`	`quantity<time>`	Worst-case execution time.
`period`	`quantity<time>`	Activation period.
`deadline`	`quantity<time>`	Completion deadline.
`frequency`	`quantity<frequency>`	Activation frequency.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).

OperationalExchange

Interaction between operational entities.

Arcadia: CommunicationMean / OperationalExchange
SysML v2: connect

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Element>`	Source element or port.
`to`	`ref<Element>`	Target element or port.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.

OperationalProcess

Ordered path of activities fulfilling a capability.

Arcadia: OperationalProcess
SysML v2: action def (sequence)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`involves`	`list<ref<Element>>`	Ordered functions, exchanges and chains of the chain.
`latency_budget`	`quantity<time>`	End-to-end budget checked by the gate.
`capability`	`ref<Capability>`	Capability this chain exemplifies.

System Analysis

Requirement

Stakeholder, system or safety requirement.

Arcadia: Requirement
SysML v2: requirement

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`priority`	`enum Priority`	Business priority.
`category`	`text`	Requirement category (functional, performance, safety...).
`rationale`	`text`	Why the requirement exists.
`source`	`text`	Origin document or stakeholder.
`status`	`text`	Lifecycle status.
`verification_method`	`enum VerificationMethod`	Intended verification method.
`parent`	`ref<Requirement>`	Requirement it sits under in its document (ReqIF SPEC-HIERARCHY); structure, not refinement.
`reqif_id`	`text`	Identifier the requirement has in the tool it came from (ReqIF IDENTIFIER), given back on export.
`applies_to`	`list<ref<Configuration>>`	The configurations of the product line the requirement holds for; every one when absent. A case verifying it runs in one of them, and the gate wants a case in each.
`frames`	`list<ref<Concern>>`	The concerns the requirement addresses (SysML v2 `frame`).
`subject`	`ref<Element>`	What the requirement is about: a component, a node, a function (SysML v2 `subject`). The element shows it in its requirements compartment.
`require`	`list<text>`	Constraints the subject must meet, as expressions (`"mass <= 1200 kg"`; SysML v2 `require constraint`).
`assume`	`list<text>`	Constraints taken for granted for the requirement to hold (`"ambient >= -20 °C"`; SysML v2 `assume constraint`).
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).

Concern

What a stakeholder cares about, framed by the requirements that address it. Declared in a requirements block: concern "Resists to bullets" { stakeholders: ["Owner"] }.

Arcadia: (none: carried as a requirement)
SysML v2: concern

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`stakeholders`	`list<text>`	Who has the concern (SysML v2 `stakeholder`).
`rationale`	`text`	Why it matters.
`parent`	`ref<Concern>`	Concern it sits under.

Mission

High-level goal the system contributes to.

Arcadia: Mission
SysML v2: use case def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.

Capability

Expected ability of the system. May be declared inside another capability.

Arcadia: Capability
SysML v2: use case def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`mission`	`ref<Mission>`	Mission this capability contributes to.
`realizes`	`ref<OperationalCapability>`	Operational capability realized.
`involves`	`list<ref<Element>>`	Functions, actors and chains involved.
`extends`	`list<ref<Capability>>`	Capabilities of the same level this one extends.
`includes`	`list<ref<Capability>>`	Capabilities of the same level this one includes.
`specializes`	`list<ref<Capability>>`	Capabilities of the same level this one is a special case of.

SystemFunction

Function the system performs.

Arcadia: SystemFunction
SysML v2: action def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`category`	`text`	Functional category (free text).
`inputs`	`list<text>`	Input data names.
`outputs`	`list<text>`	Output data names.
`latency`	`quantity<time>`	Execution latency; summed along functional chains by the gate.
`execution_time`	`quantity<time>`	Alias of latency.
`wcet`	`quantity<time>`	Worst-case execution time.
`period`	`quantity<time>`	Activation period.
`deadline`	`quantity<time>`	Completion deadline.
`frequency`	`quantity<frequency>`	Activation frequency.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).

FunctionPort

Oriented port of a function (strictly in XOR out).

Arcadia: FunctionInputPort / FunctionOutputPort
SysML v2: in/out item

Attribute	Type	Meaning
`data_type`	`text`	Exchanged data type.
`type`	`enum PortKind`	data

FunctionalExchange

Data flow between function ports.

Arcadia: FunctionalExchange
SysML v2: flow

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Element>`	Source element or port.
`to`	`ref<Element>`	Target element or port.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.

SystemActor

External actor at system level.

Arcadia: SystemActor
SysML v2: part def (actor)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).

SystemComponent

The system or one of its external components.

Arcadia: SystemComponent
SysML v2: part def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`type`	`text`	Component category (free text).
`layer`	`text`	Overrides the architectural layer label.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.

FunctionalChain

Ordered functions, exchanges and chains realizing one dataflow path; control nodes and sequence links branch it.

Arcadia: FunctionalChain
SysML v2: action def (sequence)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`involves`	`list<ref<Element>>`	Ordered functions, exchanges and chains of the chain.
`latency_budget`	`quantity<time>`	End-to-end budget checked by the gate.
`capability`	`ref<Capability>`	Capability this chain exemplifies.

ControlNode

Control node of a functional chain: control and|or|iterate "Name", joined to the chain's steps by sequence links.

Arcadia: ControlNode
SysML v2: fork / join / decision / loop node

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`kind`	`enum ControlKind`	and

SequenceLink

sequence "A" -> "B" { condition: "..." } inside a chain: each end a step of the chain or one of its control nodes.

Arcadia: SequenceLink
SysML v2: succession

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`condition`	`text`	Guard of the branch.

Logical Architecture

LogicalComponent

Behavioral building block, may be nested. In a product line, a component variation: true holds the components that are its variants (variant: true).

Arcadia: LogicalComponent
SysML v2: part def + part

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`type`	`text`	Component category (free text).
`layer`	`text`	Overrides the architectural layer label.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.
`multiplicity`	`multiplicity`	How many of the element its owner has: a count (`4`) or a range as text (`"0..1"`, `"1.."`, `""`). One when absent.
`variation`	`boolean`	A point of variation: the components it holds marked `variant` are the choices.
`variant`	`boolean`	One variant of the variation holding it.

LogicalFunction

Function of the logical level, declared inside the component that performs it (or at the level, unallocated), with its ports and sub-functions; realizes: names the system function it realizes.

Arcadia: LogicalFunction
SysML v2: action def (perform)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`category`	`text`	Functional category (free text).
`inputs`	`list<text>`	Input data names.
`outputs`	`list<text>`	Output data names.
`latency`	`quantity<time>`	Execution latency; summed along functional chains by the gate.
`execution_time`	`quantity<time>`	Alias of latency.
`wcet`	`quantity<time>`	Worst-case execution time.
`period`	`quantity<time>`	Activation period.
`deadline`	`quantity<time>`	Completion deadline.
`frequency`	`quantity<frequency>`	Activation frequency.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).

ComponentPort

Oriented port of a component (in, out, inout); it may hold ports, named Owner.port.sub.

Arcadia: ComponentPort
SysML v2: port

Attribute	Type	Meaning
`interface`	`text`	Interface type carried.
`protocol`	`text`	Protocol.
`multiplicity`	`multiplicity`	How many of the element its owner has: a count (`4`) or a range as text (`"0..1"`, `"1.."`, `""`). One when absent.
`physics`	`enum Physics`	What the port carries, for `arclang export -f modelica`: the Modelica Standard Library connector it becomes (a signal by its direction). A port saying none is not exported.
`pole`	`enum Pole`	For an electrical port: the pin it is (positive when absent).
`flange`	`enum Flange`	For a mechanical or thermal port: the flange it is (`b` for an out port, `a` otherwise, when absent).

LogicalInterface

Contract between two components.

Arcadia: Interface
SysML v2: interface def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<LogicalComponent>`	Provider.
`to`	`ref<LogicalComponent>`	Consumer.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.

ComponentExchange

Exchange between component ports; with ends, between more than two.

Arcadia: ComponentExchange
SysML v2: connect

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Element>`	Source element or port.
`to`	`ref<Element>`	Target element or port.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.
`ends`	`list<ref<Element>>`	Every end of an exchange joining more than two (`connect (a, b, c)`); drawn through a junction.

CapabilityRealization

Realization of a system capability by components. May be declared inside another realization.

Arcadia: CapabilityRealization
SysML v2: use case def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`realizes`	`ref<Capability>`	Capability realized.
`involves`	`list<ref<Element>>`	Components and chains involved.
`extends`	`list<ref<CapabilityRealization>>`	Capabilities of the same level this one extends.
`includes`	`list<ref<CapabilityRealization>>`	Capabilities of the same level this one includes.
`specializes`	`list<ref<CapabilityRealization>>`	Capabilities of the same level this one is a special case of.

Physical Architecture

PhysicalNode

Hardware node hosting behavior components.

Arcadia: PhysicalComponent (NODE)
SysML v2: part def + part

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`type`	`text`	Component category (free text).
`layer`	`text`	Overrides the architectural layer label.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).
`position`	`position {x, y, z}`	Where it stands in its owner (the model at the top), in lengths: `{ x: 1.2 m y: 0 m z: 0.4 m }`, a missing axis being 0. Placed so in CAD (`arclang export -f step`).
`orientation`	`orientation {yaw, pitch, roll}`	How it is turned in its owner: `{ yaw: 90 deg pitch: 0 deg roll: 0 deg }`, about z, then y, then x.
`shape`	`shape {box	cylinder}`
`multiplicity`	`multiplicity`	How many of the element its owner has: a count (`4`) or a range as text (`"0..1"`, `"1.."`, `""`). One when absent.
`processor`	`text`	Processor.
`cpu`	`text`	CPU description.
`redundancy`	`text`	Redundancy scheme.
`model`	`text`	The executable model of the element: a Modelica class extending the class `arclang export -f modelica` generates for it, with modifiers if needed (`"DronePhysics.Rotors(rho=airframe.rho)"`). The export rolls these up into `Executable.<Configuration>`, the model a simulated case without `model:` runs. Often written in a `refine` of an element imported from another tool.

PhysicalPort

Unoriented physical connector.

Arcadia: PhysicalPort
SysML v2: port

Attribute	Type	Meaning
`connector`	`text`	Connector type.
`physics`	`enum Physics`	What the port carries, for `arclang export -f modelica`: the Modelica Standard Library connector it becomes (a signal by its direction). A port saying none is not exported.
`pole`	`enum Pole`	For an electrical port: the pin it is (positive when absent).
`flange`	`enum Flange`	For a mechanical or thermal port: the flange it is (`b` for an out port, `a` otherwise, when absent).

BehaviorComponent

Software/behavior deployed on a node; declares the physical functions it performs.

Arcadia: PhysicalComponent (BEHAVIOR)
SysML v2: part

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).
`position`	`position {x, y, z}`	Where it stands in its owner (the model at the top), in lengths: `{ x: 1.2 m y: 0 m z: 0.4 m }`, a missing axis being 0. Placed so in CAD (`arclang export -f step`).
`orientation`	`orientation {yaw, pitch, roll}`	How it is turned in its owner: `{ yaw: 90 deg pitch: 0 deg roll: 0 deg }`, about z, then y, then x.
`shape`	`shape {box	cylinder}`
`model`	`text`	The executable model of the element: a Modelica class extending the class `arclang export -f modelica` generates for it, with modifiers if needed (`"DronePhysics.Rotors(rho=airframe.rho)"`). The export rolls these up into `Executable.<Configuration>`, the model a simulated case without `model:` runs. Often written in a `refine` of an element imported from another tool.

PhysicalFunction

Function of the physical level, declared inside the behavior component that performs it (or at the level, unallocated), with its ports and sub-functions; realizes: names the logical function it realizes.

Arcadia: PhysicalFunction
SysML v2: action def (perform)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`category`	`text`	Functional category (free text).
`inputs`	`list<text>`	Input data names.
`outputs`	`list<text>`	Output data names.
`latency`	`quantity<time>`	Execution latency; summed along functional chains by the gate.
`execution_time`	`quantity<time>`	Alias of latency.
`wcet`	`quantity<time>`	Worst-case execution time.
`period`	`quantity<time>`	Activation period.
`deadline`	`quantity<time>`	Completion deadline.
`frequency`	`quantity<frequency>`	Activation frequency.
`safety_level`	`enum SafetyLevel`	ASIL, DAL or SIL assigned to the element.
`asil`	`enum Asil`	ISO 26262 ASIL (QM, ASIL-A..D).
`dal`	`enum Dal`	DO-178C design assurance level (DAL-A..E).

HardwareComponent

Hardware part of a node.

Arcadia: PhysicalComponent (NODE, nested)
SysML v2: part

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.

PhysicalLink

Physical medium between nodes or ports.

Arcadia: PhysicalLink
SysML v2: connect (binding)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Element>`	Source element or port.
`to`	`ref<Element>`	Target element or port.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.
`route`	`list<location {lat, lon[, alt]}>`	The way the link takes on the Earth, at least two points: `[{ lat: .. lon: .. }, { lat: .. lon: .. }]`. Its length is measured; a declared `length` may not be shorter.
`length`	`quantity<length>`	Length of the medium. Not shorter than its route, nor than the distance between located ends; with `latency`, light must cover it in that time.
`max_length`	`quantity<length>`	Longest the medium may be (a cable or bus limit): the route and the length must keep within it.

PhysicalExchange

Message routed over a link.

Arcadia: ComponentExchange (physical)
SysML v2: flow

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Element>`	Source element or port.
`to`	`ref<Element>`	Target element or port.
`protocol`	`text`	Transport protocol (CAN FD, Ethernet, ARINC 429...).
`bandwidth`	`quantity<data rate>`	Available or required data rate.
`latency`	`quantity<time>`	Transport latency.
`frequency`	`quantity<frequency>`	Message rate.
`period`	`quantity<time>`	Message period.
`size`	`quantity<data size>`	Payload size.
`data_type`	`text`	Exchanged data type.
`via`	`ref<PhysicalLink>`	Carrying link.
`message_type`	`text`	Message/frame type.

Deployment

Allocation of a logical component to a node.

Arcadia: ComponentDeploymentLink
SysML v2: allocate

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.

PhysicalPath

Ordered links routing an exchange.

Arcadia: PhysicalPath
SysML v2: connect (sequence)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`involves`	`list<ref<PhysicalLink>>`	Ordered links.

EPBS

EpbsSystem

Top configuration item.

Arcadia: ConfigurationItem (SYSTEM)
SysML v2: part def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).
`position`	`position {x, y, z}`	Where it stands in its owner (the model at the top), in lengths: `{ x: 1.2 m y: 0 m z: 0.4 m }`, a missing axis being 0. Placed so in CAD (`arclang export -f step`).
`orientation`	`orientation {yaw, pitch, roll}`	How it is turned in its owner: `{ yaw: 90 deg pitch: 0 deg roll: 0 deg }`, about z, then y, then x.
`shape`	`shape {box	cylinder}`

EpbsSubsystem

Subsystem configuration item.

Arcadia: ConfigurationItem (CS)
SysML v2: part def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).
`position`	`position {x, y, z}`	Where it stands in its owner (the model at the top), in lengths: `{ x: 1.2 m y: 0 m z: 0.4 m }`, a missing axis being 0. Placed so in CAD (`arclang export -f step`).
`orientation`	`orientation {yaw, pitch, roll}`	How it is turned in its owner: `{ yaw: 90 deg pitch: 0 deg roll: 0 deg }`, about z, then y, then x.
`shape`	`shape {box	cylinder}`

EpbsItem

Leaf configuration item or assembly.

Arcadia: ConfigurationItem (HW/SW)
SysML v2: part def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`part_number`	`text`	Part number.
`supplier`	`text`	Supplier.
`memory`	`text`	Memory configuration, descriptive (`"2 GB DDR4, 64 GB eMMC"`). Use `ram`/`flash`/`storage` for typed sizes.
`ram`	`quantity<data size>`	RAM capacity.
`flash`	`quantity<data size>`	Flash capacity.
`storage`	`quantity<data size>`	Mass storage capacity.
`power`	`quantity<power>`	Power consumption.
`voltage`	`quantity<voltage>`	Supply voltage.
`mass`	`quantity<mass>`	Mass.
`weight`	`quantity<mass>`	Alias of mass.
`location`	`location {lat, lon[, alt]}`	Where it stands on the Earth, WGS 84: `{ lat: 48.8566 deg lon: 2.3522 deg alt: 35 m }` (`alt` optional). Drawn on maps (`arclang export -f geojson`).
`position`	`position {x, y, z}`	Where it stands in its owner (the model at the top), in lengths: `{ x: 1.2 m y: 0 m z: 0.4 m }`, a missing axis being 0. Placed so in CAD (`arclang export -f step`).
`orientation`	`orientation {yaw, pitch, roll}`	How it is turned in its owner: `{ yaw: 90 deg pitch: 0 deg roll: 0 deg }`, about z, then y, then x.
`shape`	`shape {box	cylinder}`

Data model

Class

Structured data element; every attribute but id, description and extends is a field, kept in declared order.

Arcadia: Class
SysML v2: attribute def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`extends`	`ref<Class>`	The class this one specializes.

Association

Association between two classes, as an element of its own; from owns the navigable end.

Arcadia: Association
SysML v2: connection def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`from`	`ref<Class>`	The class owning the navigable end.
`to`	`ref<Class>`	The class at the navigable end.
`role`	`text`	The field of `from` typed by `to` (the navigable end).
`kind`	`enum AssociationKind`	association
`multiplicity`	`text`	Multiplicity of the navigable end (`1`, `0..*`).

Enumeration

Enumerated data type.

Arcadia: Enumeration
SysML v2: enum def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`values`	`list<text>`	Literals.

DataType

Primitive data type.

Arcadia: DataType
SysML v2: attribute def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`base`	`text`	Base type.
`unit`	`enum Unit`	Unit symbol of the values.

ExchangeItem

Set of data elements exchanged together.

Arcadia: ExchangeItem
SysML v2: item def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`mechanism`	`enum ExchangeMechanism`	Exchange mechanism.
`elements`	`list<ref<Class>>`	Grouped data elements.

Transverse

Hazard

HARA entry: hazardous event and its classification.

Arcadia: (safety extension)
SysML v2: requirement (hazard)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`severity`	`enum HazardSeverity`	ISO 26262 S0-S3 or DO-178C failure condition.
`exposure`	`enum Exposure`	ISO 26262 E0-E4.
`controllability`	`enum Controllability`	ISO 26262 C0-C3.
`condition`	`enum FailureCondition`	DO-178C failure condition class.
`asil`	`enum Asil`	Declared ASIL; must match S/E/C.
`dal`	`enum Dal`	Declared DAL; must match the condition.
`sil`	`enum Sil`	IEC 61508 SIL of the hazard (SIL-1..SIL-4); classifies it without S/E/C.
`mitigated_by`	`list<ref<Requirement>>`	Safety requirements mitigating the hazard.
`gate`	`text`	Fault tree: `or` (default, one failure mode leading to it suffices) or `and` (all of them, a redundancy).
`budget_fit`	`number`	Fault tree: the most its rate may be, in FIT; else the target of its ASIL, failure condition, DAL or SIL.
`mission_time`	`quantity<time>`	Fault tree: the exposure the probability is computed over (1 h by default).

FmeaEntry

FMEA line: failure mode with S/O/D rating.

Arcadia: (safety extension)
SysML v2: requirement (failure mode)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`failure_mode`	`text`	Failure mode.
`effect`	`text`	Effect.
`cause`	`text`	Cause.
`severity`	`text`	Severity: rating, class (S3) or description — free text by design, FMEA practices differ.
`occurrence`	`text`	Occurrence: rating, class or rate description.
`detection`	`text`	Detection: rating, class or detection means.
`rpn`	`number`	Risk priority number.
`element`	`ref<Element>`	The element that fails.
`leads_to`	`list<ref<Hazard>>`	The hazards this failure mode leads to: the fault trees it is a basic event of.
`fit`	`number`	Failure rate in FIT (failures per 10^9 hours).

Threat

Threat of a cybersecurity analysis: what an attacker may achieve, applied to primary assets and involving components. Its security needs are the free security_<need> attributes, checked against security_scales.

Arcadia: cybersecurity:Threat (Cybersecurity viewpoint)
SysML v2: requirement (threat)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`kind`	`text`	Threat kind: one of `security_scales.threat_kinds` when declared.
`level`	`number`	Criticality level of the threat (an integer).
`rationale`	`text`	Why the threat is assessed so.
`applies_to`	`list<ref<PrimaryAsset>>`	Primary assets the threat applies to.
`involves`	`list<ref<Element>>`	Components, entities or actors involved.

PrimaryAsset

Primary asset of a cybersecurity analysis: a service, information or business concern to protect, made of declared elements.

Arcadia: cybersecurity:FunctionalPrimaryAsset / InformationPrimaryAsset / EnterprisePrimaryAsset
SysML v2: requirement (asset)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`kind`	`enum AssetKind`	What the asset is.
`members`	`list<ref<Element>>`	Functions, exchange items or classes making up the asset.

Trace

Typed link between two elements.

Arcadia: AbstractTrace / Realization
SysML v2: satisfy / verify / allocate

Attribute	Type	Meaning
`from`	`ref<Element>`	Source.
`to`	`ref<Element>`	Target.
`type`	`enum TraceKind`	Link kind.
`rationale`	`text`	Justification.

Configuration

One product of a product line: the variant it selects in each variation. Two variants of one variation are an error, a variation left open a warning.

Arcadia: (product line)
SysML v2: part (#Configuration)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`selects`	`list<ref<LogicalComponent>>`	The variants selected, one per variation.

IoBinding

io_binding "ECU" { ... }: the inputs and outputs of a state machine bound once to the channels of the I/O interface arclang_io.h (gpio, adc, dac, pwm, can, uart, with a clock and a watchdog). Checked by the compiler, against its target's channels too; arclang export -f c generates the glue that calls the channels, arclang sil runs it on the host board, arclang pil on the target's processor. See docs/embedded-c.md.

Arcadia: (embedded extension)
SysML v2: (none: an allocation of a state machine's events, conditions, states and actions to I/O channels)

Attribute	Type	Meaning
`machine`	`ref<StateMachine>`	The state machine bound (optional when the model has one).
`period`	`quantity<time>`	The step period on the target, a time (`10 ms`): the glue runs one cycle per period.
`watchdog`	`boolean`	Kick the watchdog after every cycle that read, stepped and wrote without error.
`target`	`text`	The target package it is deployed on (`zephyr/litex_vexriscv`; `host` by default): the compiler checks that the target has every channel bound. `arclang export -f zephyr` and `arclang pil` use it. See docs/embedded-targets.md.
`inputs`	`list<text>`	`event or condition <- channel`: an event from an edge (`gpio 4 rising`), a frame (`can 0x120`) or a byte (`uart 0 0x41`); a condition from a level (`gpio 3`), a raw threshold (`adc 0 > 2048`) or the first byte of the last frame (`can 0x121`). An event bound to a level, a condition to an edge, or an input bound twice is an error; an input left unbound, a warning.
`outputs`	`list<text>`	`state or action -> channel`: a state (1 while active) or an action (times run in the step) written to `gpio 10`, `pwm 2 750` (per mille while not zero), `dac 1 4095` (while not zero), `can 0x300` (first byte, every period) or `uart 1 0x45` (each step it is not zero). A channel written twice, or a pin both read and written, is an error.
`description`	`text`	Free-text description.

TestCase

Verification case covering requirements.

Arcadia: (V&V extension)
SysML v2: verification def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`verifies`	`list<ref<Requirement>>`	Requirements verified.
`method`	`enum VerificationMethod`	Verification method.
`procedure`	`text`	Procedure.
`expected`	`text`	Expected result.
`asserts`	`list<ref<Constraint>>`	An analysis: the constraints whose evaluation is its verdict (pass when they all hold).
`verdict`	`enum Verdict`	Outcome of a test run elsewhere; computed, not given, when the case `asserts:` constraints or `simulate:`s. A requirement with a failing case is not verified.
`simulate`	`{backend, model, configuration, stop_time, start_time, sources, tolerance, intervals, sweep, uncertain, samples, seed, probability, confidence, mission}`	Verified by simulation: the `backend` (`openmodelica`, the default; `fmu` and `command` are declared, not built yet), the Modelica `model` to simulate (extending a system model of `arclang export -f modelica`; without it, the roll-up of the configuration, `Executable.<Configuration>`, when its elements carry `model:`), the `configuration` it is, a `mission` (a file of parameter values, one `"Element".parameter = value` a line, relative to the model file, added to the sweep), `stop_time` (and `start_time`), the hand-written Modelica `sources` (paths from the model file), `tolerance`, `intervals`, and a `sweep` (`["body.mass = 1800 kg, 2100 kg", "vcu.target_speed = 80 km/h .. 130 km/h step 10 km/h"]`: every combination is simulated, and the expectations must hold at each). Or `uncertain` parameters (`["body.mass ~ normal(1850 kg, 40 kg)", "cell.capacity ~ uniform(58 kWh, 62 kWh)", "drive.efficiency ~ normal(0.9, 0.03) in [0.8, 0.97]"]`: `normal`, `uniform` or `triangular`, kept between bounds by `in [low, high]`) drawn in `samples` (10 to 1000, default 200) from a `seed`: the case passes when the probability that the expectations hold is shown, at `confidence` (default 0.95), to reach `probability` (the Clopper-Pearson lower bound). Run by `arclang verify`; the verdict is cached, and inconclusive when stale or never run.
`execute`	`{machine, step, stop_time, inputs, binding, tolerance, quantisation, plant}`	Verified by executing a state machine at fixed step: the `machine`, the `step` (default the binding's period, else 10 ms), `stop_time`, the `inputs` (`["0 s: main switch on", "10 ms: LF-022", "300 ms: main switch on = false"]`: an event occurs in the step at its time, a condition holds or not from it on, an `in` variable takes a value from it on: `"100 ms: speed = 50 km/h"`), a `binding` (the run then goes through the I/O glue and the host board) and the `tolerance` of the comparison with the C (`quantisation`: of the fixed point of a machine allocated to programmable logic against the model, in `arclang hdl` and `arclang soc`). The expectations read the states (`"Machine".State`, 1 while active), the actions (`"Machine".action.close_contactors`, times run in the step) and the variables (`"Machine".speed`, in their unit). Compiling runs the model and reports a failing case; `arclang sil` runs the generated C against it.
`snapshots`	`list<text>`	Snapshots the simulation must reach: a snapshot, a timeslice (its snapshots) or an element (all its snapshots), by id (`["LC-DRONE.Takeoff.At cruise"]`). Each value of each one, at its `at:`, is an expectation within the snapshot's tolerance (`at(40 s, "LC-DRONE".altitude) == 120 m within 1 %`).
`expects`	`list<text>`	What the simulation result must show: comparisons over its variables read with `min`, `max`, `final`, `initial`, `mean` or `at(t, var)`, with units (`final(vehicle.distance) >= 300 km`); `==` and `!=` may say how far equal may be (`at(1 h, battery.soc) == 0.7 within 2 %`, or `within 0.05`). A comparison may name the requirement it checks (`"REQ-SHED: at(40 min, cabin.drawn) <= 1 W"`): each requirement is then judged on the comparisons naming it and those naming none.
`reviewed`	`list<text>`	The verifications reviewed: one entry per verified requirement, the requirement and the fingerprints of the case and of the requirement, written by `arclang trace --review`. A verification whose case or requirement changed since is suspect, and so is one the case verifies but does not name here.

Model

The model itself: root of the element graph, owner of every top-level element.

Arcadia: Project / SystemEngineering
SysML v2: package

Attribute	Type	Meaning
`name`	`text`	Model name.
`version`	`text`	Model version.
`description`	`text`	Free-text description.

Type

Reusable definition: type Name extends Base { ... }. Declares typed attributes, ports and the attributes instances must provide. Redefinitions must keep the dimension. Types have their own namespace. A type with ports typing a port is a port definition (its ports are the ports the port holds); typing an exchange, an interface definition; with from_kind and to_kind, typing an allocates trace, an allocation definition.

Arcadia: (extension — closest Capella notion: REC/RPL)
SysML v2: abstract part / action / port / connection / allocation def, specialized with :>

Attribute	Type	Meaning
`required`	`list<text>`	Attributes every instance must provide (declared or inherited).
`description`	`text`	Free-text description (not inherited).
`from_kind`	`text`	For an allocation definition: the kind every allocation of it goes from (`PhysicalNode`).
`to_kind`	`text`	For an allocation definition: the kind every allocation of it goes to (`LogicalComponent`).
`physics`	`enum Physics`	For a port definition: what the ports it types carry, for the Modelica export.

Note

A text about elements, declared at the top of a file (note "Text" { about: ["LC-A"] }): drawn on every view that draws one of them, tied to each by a dashed line. An element it names that the model does not declare is an error.

Arcadia: Note (diagram annotation)
SysML v2: comment about

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`about`	`list<ref<Element>>`	The elements the note is about.

Constraint

Dimension-checked comparison over typed attributes (assert: <expression>). Ill-formed is a compile error; violated is a warning and a gate blocker.

Arcadia: Constraint
SysML v2: assert constraint

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.

Timeslice

A stretch of an element's life, declared in it (timeslice "Takeoff" { start: 0 s end: 40 s }); holds the snapshots it goes through. Its other attributes are the values the element has during it.

Arcadia: (none: carried as a property)
SysML v2: timeslice

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`start`	`quantity<time>`	When it starts.
`end`	`quantity<time>`	When it ends; not before it starts.

Snapshot

One moment of an element's life, declared in it or in one of its timeslices (snapshot "Landed" { at: 5 min altitude: 0 m }). Its other attributes are the values the element has then; a value the element declares as a quantity keeps its dimension.

Arcadia: (none: carried as a property)
SysML v2: snapshot

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`at`	`quantity<time>`	When it is; within its timeslice.
`tolerance`	`text`	How far a simulated value may be from the snapshot's and still reach it, when a test case checks it: a percentage of the value (`2 %`) or an amount (`0.5 m`). 1 % when absent.

StateMachine

Modes and states of an element.

Arcadia: StateMachine
SysML v2: state def

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`initial`	`ref<State>`	Initial state.
`variables`	`list<text>`	Typed variables (SysML v2 attributes): `[in
`equations`	`list<text>`	Difference equations evaluated every step in the order written, before the transitions: `target = expression` over the variables, with the blocks `delay`, `integrator`, `pid` and the functions `min`, `max`, `abs`, `saturate`, `gain`. Typed and unit-checked.

State

State (undergone) or mode (chosen behavior).

Arcadia: State / Mode
SysML v2: state

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.

Transition

Transition between states.

Arcadia: StateTransition
SysML v2: transition

Attribute	Type	Meaning
`trigger`	`text`	Triggering event.
`guard`	`text`	Guard condition: an expression over the machine's variables (`speed > 30 km/h and armed`), else prose (a condition the reader sets).
`action`	`text`	Effect: assignments to the machine's variables (`count := count + 1; on := true`), else prose (reported, not executed).
`timing`	`quantity<time>`	Timing constraint: without a trigger, a timer (as `after:`); beside a trigger, a budget (as `budget:`).
`after`	`quantity<time>`	A timer: the transition fires when its source has been active this long (SysML v2 `accept after`). Not with a trigger.
`budget`	`quantity<time>`	A budget: how long the source may stay active before the transition fires; watched every step, an overrun is an output (`"Machine".budget.<transition>`), never a timer.
`priority`	`number`	Priority among concurrent transitions.

Diagram

A declared diagram: a named view cut from one Arcadia level, drawing the elements it names, what holds them and the exchanges between them. context: true adds the elements an exchange ties to a named one.

Arcadia: Diagram (DiagramRepresentation)
SysML v2: view

Attribute	Type	Meaning
`view`	`identifier`	The view it is cut from: oab, sab, lab, pab, cap, cdb or pbs.
`shows`	`list<ref<Element>>`	Elements drawn, by id or name; their containers are drawn around them.
`context`	`boolean`	Also draw the elements an exchange ties to a shown one.
`under`	`ref<Element>`	Draw what is under this element (instead of `shows`).
`tagged`	`list<text>`	Draw only the elements carrying one of these tags (`tags:`), with what holds them.
`configuration`	`ref<Configuration>`	Draw the view of one configuration: without the variants it does not select.
`description`	`text`	Free-text description.

Table

A live table or matrix, computed by the compiler on every change: requirements_coverage (text, satisfied by, verified by with verdicts, gate status), traceability_matrix, allocation_matrix, interface_n2, icd or elements. It belongs to the layer its scope names. arclang table writes it as JSON, CSV, TSV, Markdown, HTML or Excel.

Arcadia: (extension; Siemens/Cameo: generic or coverage table)
SysML v2: view (render asElementTable)

Attribute	Type	Meaning
`kind`	`identifier`	requirements_coverage, traceability_matrix, allocation_matrix, interface_n2, icd or elements.
`scope`	`text`	What the rows are taken from: a layer (OA, SA, LA, PA, EPBS) or an element, by id or name.
`row_type`	`text`	The kind of the rows (`elements`: any kind of this metamodel; several separated by commas).
`columns`	`list<text>`	The columns shown, in order; for a matrix, the kinds (or layers) of its columns.
`rows`	`list<text>`	For a matrix: the kinds (or layers) of its rows.
`kinds`	`list<text>`	For a traceability matrix: the trace kinds shown and created.
`filter`	`text`	Rows kept: words, `column:text`, `column=text`, `column!=text`, `is:gap`, `-term` (all must match).
`gaps_only`	`boolean`	Keep only the rows with a gap or a failure.
`description`	`text`	Free-text description.

Scenario

Sequence of messages between participants.

Arcadia: Scenario
SysML v2: interaction (sequence)

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.
`participants`	`list<ref<Element>>`	Lifelines.

Fragment

A combined fragment of a scenario: alt, opt, loop, par, seq or critical, framing the messages it holds, with its operands. Fragments nest.

Arcadia: CombinedFragment
SysML v2: combined fragment

Attribute	Type	Meaning
`label`	`text`	The guard or the condition shown in the frame's tag.

StateFragment

A state, mode or function asserted on a lifeline: state "Lifeline" "Armed" { ... } / function "Lifeline" "Sense" { ... }, spanning the messages of its body (an instant without any).

Arcadia: StateFragment
SysML v2: state invariant

Attribute	Type	Meaning
`id`	`identifier`	Stable identity; drives the UUIDv5. Defaults to the name.
`name`	`text`	Display name; overrides the block name.
`description`	`text`	Free-text description.
`is`	`ref<Type>`	User-defined type of the element, or a list of types; their attributes (and ports, for components) are inherited.
`tags`	`list<text>`	Tags the element carries (`["Safety"]`): a declared diagram draws what carries one with `tagged:`. In SysML v2, metadata usages of definitions in a `Tags` package.

Message

Message between two participants.

Arcadia: SequenceMessage
SysML v2: message

Attribute	Type	Meaning
`type`	`enum MessageKind`	sync
`timing`	`quantity<time>`	Timing constraint.

Relationships

The element graph served by the Systems Modeling API (/api/systems-modeling) is made of the kinds above and of these relationship types. A relationship whose end does not resolve is reported in the commit, never dropped.

Relationship	Source	Target	Meaning
`Trace`	element	element	A `trace` declaration; `traceKind` is one of the TraceKind values.
`Verification`	TestCase	Requirement	`verifies:` of a test case.
`Annotation`	Note	element	`about:` of a note.
`Mitigation`	Requirement	Hazard	`mitigated_by:` of a hazard.
`ThreatApplication`	Threat	PrimaryAsset	`applies_to:` of a threat.
`ThreatInvolvement`	Threat	component, entity or actor	`involves:` of a threat.
`AssetMember`	PrimaryAsset	element	`members:` of a primary asset.
`Typing`	element or PhysicalLink	Type	`is:` — the element is an instance of the type.
`Specialization`	Type	Type	`extends` — the source type specializes the target.
`Involvement`	chain, path, capability	element	`involves:`; `order` is the 1-based position.
`SequenceLink`	step or ControlNode	step or ControlNode	`sequence A -> B` of a functional chain; `condition` is its guard.
`Association`	Class	Class	An `association` declaration; `kind`, `role` and `multiplicity` describe the navigable end.
`Realization`	capability	capability	`realizes:` across layers.
`CapabilityExtend`	capability	capability of the same level	`extends:` of a capability.
`CapabilityInclude`	capability	capability of the same level	`includes:` of a capability.
`CapabilityGeneralization`	capability	capability of the same level	`specializes:` of a capability.
`Contribution`	Capability	Mission	`mission:` of a capability.
`Deployment`	LogicalComponent	PhysicalNode	`deploys` / `deployment`.
`OperationalExchange`	operational entity	operational entity	Interaction or communication means.
`FunctionalExchange`	FunctionPort or function	FunctionPort or function	Data flow between functions.
`ComponentExchange`	ComponentPort or component	ComponentPort or component	Exchange between components.
`LogicalInterface`	LogicalComponent	LogicalComponent	Interface contract between two components.
`PhysicalLink`	PhysicalNode	PhysicalNode	Physical medium; carries typed attributes and may be typed.
`PhysicalExchange`	PhysicalNode	PhysicalNode	Message routed over a link.
`Transition`	State	State	State machine transition.
`Message`	element	element	Scenario message; `order` is the 1-based position.

Enumerations

Values match ignoring case and the separators -, _ and space.

Enumeration	Values	Meaning
ControlKind	`and`, `or`, `iterate`	Kind of a control node of a functional chain.
AssociationKind	`association`, `aggregation`, `composition`	Kind of an association between classes.
AssetKind	`functional`, `information`, `enterprise`	What a primary asset is (Capella's three PrimaryAsset metaclasses).
Asil	`QM`, `ASIL-A`, `ASIL-B`, `ASIL-C`, `ASIL-D`	ISO 26262 automotive safety integrity level.
Dal	`DAL-A`, `DAL-B`, `DAL-C`, `DAL-D`, `DAL-E`	DO-178C design assurance level.
Sil	`SIL-1`, `SIL-2`, `SIL-3`, `SIL-4`	IEC 61508 safety integrity level.
SafetyLevel	`QM`, `ASIL-A`, `ASIL-B`, `ASIL-C`, `ASIL-D`, `DAL-A`, `DAL-B`, `DAL-C`, `DAL-D`, `DAL-E`, `SIL-1`, `SIL-2`, `SIL-3`, `SIL-4`	Any integrity level: ASIL (ISO 26262), DAL (DO-178C) or SIL (IEC 61508).
Priority	`Critical`, `High`, `Medium`, `Low`	Requirement priority.
HazardSeverity	`S0`, `S1`, `S2`, `S3`, `Catastrophic`, `Hazardous`, `Major`, `Minor`, `No Effect`	ISO 26262 severity class or DO-178C failure condition.
Exposure	`E0`, `E1`, `E2`, `E3`, `E4`	ISO 26262 exposure class.
Controllability	`C0`, `C1`, `C2`, `C3`	ISO 26262 controllability class.
FailureCondition	`Catastrophic`, `Hazardous`, `Major`, `Minor`, `No Effect`	DO-178C failure condition classification.
VerificationMethod	`test`, `analysis`, `inspection`, `demonstration`	Verification method.
Physics	`signal`, `electrical`, `mechanical_translational`, `mechanical_rotational`, `thermal`, `fluid`	What a port carries, for the Modelica export: the Modelica Standard Library connector it becomes (`fluid` is not exported yet).
Pole	`positive`, `negative`	The pin an electrical port is (`PositivePin`, `NegativePin`).
Flange	`a`, `b`	The flange (or heat port) a mechanical or thermal port is (`Flange_a`, `Flange_b`).
Verdict	`pass`, `fail`, `inconclusive`, `error`	Verdict of a verification case (SysML v2 `VerdictKind`).
ExchangeMechanism	`EVENT`, `FLOW`, `OPERATION`, `DATA`, `SHARED_DATA`	Arcadia exchange item mechanism.
TraceKind	`satisfies`, `implements`, `validates`, `verifies`, `realizes`, `refines`, `derives`, `allocates`	Traceability link kinds.
PortKind	`data`, `control`, `event`	Function port nature.
MessageKind	`sync`, `async`	Scenario message kind.
Unit	(unit table)	Any symbol of the unit table below.

Units

A quantity is <number> <unit> (latency: 25 ms). Symbols are case-sensitive. Each dimension converts to its canonical unit for arithmetic.

Symbol	Dimension	Factor to canonical	SysML v2 (SI)
`ns`	time (s)	0.000000001	`ns`
`us`	time (s)	0.000001	`us`
`µs`	time (s)	0.000001	`us`
`ms`	time (s)	0.001	`ms`
`s`	time (s)	1	`s`
`min`	time (s)	60	`min`
`h`	time (s)	3600	`h`
`Hz`	frequency (Hz)	1	`Hz`
`kHz`	frequency (Hz)	1000	`kHz`
`MHz`	frequency (Hz)	1000000	`MHz`
`GHz`	frequency (Hz)	1000000000	`GHz`
`bps`	data rate (bit/s)	1	`'bit/s'`
`bit/s`	data rate (bit/s)	1	`'bit/s'`
`kbps`	data rate (bit/s)	1000	`'kbit/s'`
`Kbps`	data rate (bit/s)	1000	`'kbit/s'`
`kbit/s`	data rate (bit/s)	1000	`'kbit/s'`
`Mbps`	data rate (bit/s)	1000000	`'Mbit/s'`
`Mbit/s`	data rate (bit/s)	1000000	`'Mbit/s'`
`Gbps`	data rate (bit/s)	1000000000	`'Gbit/s'`
`Gbit/s`	data rate (bit/s)	1000000000	`'Gbit/s'`
`Tbps`	data rate (bit/s)	1000000000000	`'Tbit/s'`
`Tbit/s`	data rate (bit/s)	1000000000000	`'Tbit/s'`
`bit`	data size (bit)	1	`bit`
`B`	data size (bit)	8	`B`
`kB`	data size (bit)	8000	`kB`
`KB`	data size (bit)	8000	`kB`
`MB`	data size (bit)	8000000	`MB`
`GB`	data size (bit)	8000000000	`GB`
`TB`	data size (bit)	8000000000000	`TB`
`KiB`	data size (bit)	8192	`KiB`
`MiB`	data size (bit)	8388608	`MiB`
`GiB`	data size (bit)	8589934592	`GiB`
`mm`	length (m)	0.001	`mm`
`cm`	length (m)	0.01	`cm`
`m`	length (m)	1	`m`
`km`	length (m)	1000	`km`
`g`	mass (kg)	0.001	`g`
`kg`	mass (kg)	1	`kg`
`t`	mass (kg)	1000	`t`
`N`	force (N)	1	`N`
`kN`	force (N)	1000	`kN`
`mV`	voltage (V)	0.001	`mV`
`V`	voltage (V)	1	`V`
`kV`	voltage (V)	1000	`kV`
`mA`	electric current (A)	0.001	`mA`
`A`	electric current (A)	1	`A`
`mW`	power (W)	0.001	`mW`
`W`	power (W)	1	`W`
`kW`	power (W)	1000	`kW`
`J`	energy (J)	1	`J`
`kJ`	energy (J)	1000	`kJ`
`Wh`	energy (J)	3600	`'W*h'`
`kWh`	energy (J)	3600000	`'kW*h'`
`Pa`	pressure (Pa)	1	`Pa`
`kPa`	pressure (Pa)	1000	`kPa`
`bar`	pressure (Pa)	100000	`bar`
`K`	temperature (K)	1	`K`
`°C`	temperature (K)	1 + 273.15	`K`
`degC`	temperature (K)	1 + 273.15	`K`
`C`	electric charge (C)	1	`C`
`mAh`	electric charge (C)	3.6	`'mA*h'`
`Ah`	electric charge (C)	3600	`'A*h'`
`mOhm`	resistance (Ohm)	0.001	`'mΩ'`
`Ohm`	resistance (Ohm)	1	`'Ω'`
`Ω`	resistance (Ohm)	1	`'Ω'`
`mΩ`	resistance (Ohm)	0.001	`'mΩ'`
`kOhm`	resistance (Ohm)	1000	`'kΩ'`
`kΩ`	resistance (Ohm)	1000	`'kΩ'`
`W/K`	thermal conductance (W/K)	1	`'W/K'`
`kW/K`	thermal conductance (W/K)	1000	`'kW/K'`
`J/K`	heat capacity (J/K)	1	`'J/K'`
`kJ/K`	heat capacity (J/K)	1000	`'kJ/K'`
`MJ/K`	heat capacity (J/K)	1000000	`'MJ/K'`
`cm²`	area (m²)	0.0001	`'cm²'`
`m²`	area (m²)	1	`'m²'`
`m2`	area (m²)	1	`'m²'`
`kg/s`	mass flow rate (kg/s)	1	`'kg⋅s⁻¹'`
`g/s`	mass flow rate (kg/s)	0.001	`'g/s'`
`m/s`	speed (m/s)	1	`'m/s'`
`km/h`	speed (m/s)	0.2777777777777778	`'km/h'`
`percent`	ratio (one)	0.01	`'%'`
`%`	ratio (one)	0.01	`'%'`
`deg`	angle (rad)	0.017453292519943295	`'°'`
`rad`	angle (rad)	1	`rad`

Traceability rules

Dangling endpoints are compile errors. Kind mismatches are metamodel: warnings.

Kind	From	To	Meaning
`satisfies`	component, function, node, actor	Requirement	Architecture element satisfies a requirement. Counted by the gate.
`implements`	component, node	function, Requirement	Element implements a function or requirement.
`verifies`	TestCase	Requirement	Verification case covers a requirement (also via `verifies:`).
`validates`	TestCase, Scenario	Requirement, Capability	Validation evidence.
`realizes`	lower-layer element	upper-layer element	Inter-layer realization: SA→OA, LA→SA, PA→LA, EPBS→PA.
`refines`	Requirement	Requirement	Requirement decomposition.
`derives`	Requirement	Requirement	A requirement derived from another (SysML `derive`): `trace "REQ-CELL-TEMP" derives "REQ-RANGE"`. Drawn on the requirements view.
`allocates`	component, node	function, component	Allocation (also expressed by nesting and `deployment`).