SysML v2

Holarch Features in SysML v2 Projects

The Holarch pages around the SysML v2 model: the lifecycle rail, interfaces, risks and decisions, planning, documents and whiteboards, frameworks, comments, history, search, collaboration and Ask AI.

How to use it →

On this page

Overview

A SysML v2 project is more than its text. It has the same lifecycle rail as an LML project: requirements, behavior, architecture, interfaces, verification, risks, planning and frameworks. These pages run on the SysML v2 model, with the same layout and controls as in LML projects.

This page covers the pages outside the model's text and views:

The navigation rail: which pages a SysML v2 project shows.
Interfaces: the Interface Register, ICDs, N² diagrams and the Physical I/O Diagram.
Risk & Decisions and Plan & Deliver: risks, tasks, change requests, baselines and the SE Process.
Documents, whiteboards and presentations.
DoDAF and UAF.
Labels, assignees, comments and history, Search and Collaboration.
Ask AI.

Requirements, verification and analysis have their own pages: see Related pages.

Concepts

The model and Holarch data

A SysML v2 project holds two kinds of data:

The model: packages, definitions, usages and relationships. Everything in it appears in the text and can be exported as .sysml or JSON.
Holarch data next to the model: risks, decisions, tasks, change requests, documents, whiteboards, budgets settings, requirement status, interface status, labels, assignees, comments and view layouts. It is not SysML text and is not part of .sysml or JSON exports.

The lifecycle pages read the model and keep their own fields as Holarch data. For example, the Interface Register reads the connections from the model and stores each interface's Interface Status and Owner as Holarch data.

Links by id

Holarch items link to model elements by the element's id, not its name. A risk caused by the part battery stays linked when you rename battery or move it to another package in the text.

How LML pages see the model

The shared pages show model elements with LML class names, so their filters, columns and reports work unchanged:

On the page	In the model
Requirement	Requirement usage or definition (number = short name, description = `doc`)
Test Case, Test Suite	Verification usage or definition; a package that owns verification cases
Asset	Part usage
Action	Action usage
Port, Conduit, Input/Output	Port usage; connection or interface usage; item definition or usage
satisfied by, verified by	`satisfy`, `verify`
performed by	`allocate` or `perform`
traced to	`dependency`
decomposed by	Owned members of the same kind

Names show in title case: the part frontAxle shows as Front Axle.

How to use it

When and why

Use these pages to run the project around the model:

Track interfaces and their status between subsystems as the architecture settles.
Record risks and decisions against the parts and requirements they concern.
Plan the work, run change control and freeze baselines for reviews.
Write specifications and review packages from live model data.
Produce DoDAF or UAF products from the same model.

Link a Holarch item to the model

Open the risk, decision, task or Measure.
In its Trace section, click + next to a relationship, such as caused by on a risk, then Link existing….
The list shows the model's parts, actions, ports, connections, requirements and verification cases.
Choose the element.
Clicking the linked element opens its Entity View.

Propose a change to the model

Open Plan & Deliver → Change Requests and create a change request.
Add the affected items from the model or from Holarch items.
Click Add Change ▾ → Change an Item… on a SysML v2 element to propose a new short name, name or documentation. Or click Edit SysML Text… to propose new text for a package.
The proposed change shows the text difference.
After review, click Apply Changes.
The model changes as one undo step.

Freeze and compare a baseline

Open Plan & Deliver → Baselines & Versions and make a project baseline.
The baseline holds the SysML v2 model as well as the Holarch items.
Later, click Compare on the baseline.
You see the elements added, removed, changed, moved and renamed, and the text changes per package.
To go back, click Restore. The model and the Holarch items return to the baseline; undo is available.

Assign an element and discuss it

Select any element in a view, the Browser or a table.
In the inspector's Item section, set Assignee and Due date, and add labels.
My Work lists the elements assigned to you.
In the Discussion section, write a comment. Type @ to mention a project member.

Worked example: the Hybrid Car demo

Create the demo first: on Manage Projects, click Project Files ▾ → New Demo Project → Hybrid Car (SysML v2).

Risks. Open Risk & Decisions → Risk Register.

R.1 Battery cell supply delay is caused by the part battery and the part definition Battery. It is mitigated by the task T.1 Qualify a second cell supplier.
R.2 Curb mass over target is caused by the parts engine and body, and mitigated by T.2 Weigh the engine prototype.

Open R.1 and read Requirements at risk: the requirements that its linked parts satisfy in the model.

Decisions. D.1 Use a lithium-ion battery pack is linked to Battery and the requirement definition BatteryCapacity.

Change request. Open Plan & Deliver → Change Requests and select Raise the battery capacity requirement. Its proposed change rewrites the documentation of BatteryCapacity; the review shows the text difference.

Document baseline. Open Needs & Requirements → Documents → Vehicle Specification. The document has the baseline SRR Baseline. The bar on the left edge of each row is blue when the item is unchanged since that baseline and amber when it changed: VR-6 Battery Mass Limit moved to In Review after the baseline.

Interfaces. Open Interfaces → Interface Register. The interfaces come from the model, for example hvBus : HighVoltageBus connect battery.powerOut to motor.powerIn; in Powertrain. Its ends are the battery and the motor, the parts that own the connected ports.

Frameworks. The package HybridCarArchitecture tags Vehicles::Powertrain as a System with metadata System about Vehicles::Powertrain;. DoDAF and UAF matrix products list it as a system.

Tips and good practice

Keep fields that describe the system in the model (values, relationships, documentation). Keep fields that describe the project (status, owners, dates, risks) as Holarch data.
Link risks and tasks to the most specific element, such as a part usage rather than its package, so Requirements at risk finds the right requirements.
Make a baseline before a large text edit or an import. Compare then shows exactly what changed.

Common mistakes

Writing status into the text. Requirement status, interface status and TBD owners shown on the lifecycle pages are Holarch data. Use the inspector, not the text; text that is not valid SysML stays a draft.
Looking for an LML-only page. Pages that SysML v2 projects do not have yet are not shown in the rail. See Limits.

SysML v2 projects have the same lifecycle groups in the rail as LML projects, plus the Model group. Pages not available for SysML v2 yet are not shown.

Group	Pages
Home	Model summary and next actions.
Needs & Requirements	Documents, Requirements, Quality, TBD/TBR, Suspect Links, Approvals.
Model	Editor (SysML v2 text), Browser, Import and Export.
Behavior	Functional Analysis, Action Flows, FFBD, State Machines, Sequences, Simulator.
Architecture	Parts, General Views, Interconnection Views, Hierarchy, Budgets & TPMs.
Interfaces	Interface Register, ICDs, N² Diagrams, Items & I/O.
Verification	RVTM, Verification Cases, Traceability Matrix, Model Checks.
Risk & Decisions	Risk Register, Trade Studies, Decisions.
Plan & Deliver	My Work, SE Process, Project Management, Charts, Whiteboards, Change Requests, Baselines & Versions, Review Packages, Presentations.
Frameworks	DoDAF, UAF.

Parts, Items & I/O, Requirements and Decisions are the Database filtered to one kind.
Action Flows, State Machines, Sequences, General Views, Interconnection Views, FFBD, Hierarchy, ICDs and N² Diagrams are the Diagrams list filtered to one kind. + New Diagram on a filtered list starts with that kind.
The Diagrams tool, the Trash and Help sit at the bottom of the rail, as in every project.

Interfaces

The Interface Register, Interface Control Diagrams (ICDs), N² diagrams and the Physical I/O Diagram work on the model's connections, interfaces and items.

What counts as an interface

Every connect and interface usage. Its ends are the parts that own the connected ports: in tank.fuelOut, the end is the tank.
It conveys the items of the flows between the same parts (flow of Fuel from tank.fuelOut to engine.fuelIn;), and the directed features of the source port's definition. out features go from the source end, in features toward it. A conjugated port (~FuelPort) reverses them.
Interface Status, Owner, TBD/TBR, Capacity, Units, Latency and the other interface attributes are Holarch data next to the model.
Requirements link to an interface with a dependency (traced from) or a satisfy.

Pages and diagrams

Page or diagram	What it does
Interface Register	Every interface with its ends, status, owner, items, requirements and capacity check. Filter by status, export CSV, export an ICD document (Word) per interface.
ICDs	An interface between its two end parts. A part usage shows its definition's parts. Drop an item definition on the interface to add a flow of that item. Change the end parts in the Editor.
N² Diagram (Parts)	The parts a part owns on the diagonal, their connections and interfaces in the cells. Drag from one part toward another to add a connection.
N² Diagram (Actions)	The actions an action owns on the diagonal, and the items they pass in the cells, from their `in` and `out` item parameters and flows.
Physical I/O Diagram (+ New Diagram)	The parts with the item lines from the actions they perform (also through redefining parts) and the connections between them, with the same warnings as in LML projects. Drag from one part to another to add a connection.

Selecting an element shows the SysML v2 inspector with the interface section and the attributes stored next to the model. Every change is one undo step. See Interfaces for the full page reference.

Risk & Decisions

Risk & Decisions works as in LML projects. Risks and decisions are Holarch items linked to model elements.

Risk Register: + New Risk, probability and consequence, handling, mitigations and the risk scale.
Linking: in a risk's Trace section, click + next to caused by → Link existing…. The list shows the model's parts, actions, ports, connections, requirements and verification cases.
Requirements at risk lists the requirements that the linked parts and actions satisfy in the model.
Decisions lists the decisions; link one to the elements it concerns the same way.
Trade Studies compare model elements as alternatives; see Evaluation, Units and Analysis in SysML v2 Projects.

See Risk and Decisions for the full page reference.

Plan & Deliver

Plan & Deliver has the same pages as in LML projects.

Page	In a SysML v2 project
My Work	Your tasks, the elements assigned to you, and the requirements awaiting your review.
SE Process	The guides (Kossiakoff, ISO/IEC/IEEE 15288, NASA, DoD and others) read requirements, satisfy and verify relationships, parts, actions and connections from the model. Checks without a SysML v2 meaning, such as stakeholder needs as statements, are not shown.
Project Management, Charts	Tasks are Holarch items; link them to model elements with Link existing….
Whiteboards	See Documents, whiteboards and presentations.
Change Requests	Affected items from the model or Holarch items. Add Change ▾ → Change an Item… proposes a new short name, name or documentation of a SysML v2 element; Edit SysML Text… proposes new text for a package. The review shows the text difference; Apply Changes changes the model as one undo step.
Baselines & Versions	A project baseline holds the SysML v2 model too. Compare lists elements added, removed, changed, moved and renamed, and the text changes per package. Restore brings the model and the Holarch items back; undo is available.
Review Packages, Presentations	As in LML projects. Presentations show views and element cards.

See Plan & Deliver for the full page reference.

Documents, whiteboards and presentations

Documents

Requirements documents: a document holds the requirement usages of one package. Choose it with Write ▾ → Requirements Package…. A new document gets a package named after it with its first requirement.
The outline, numbers, nesting, inspector, quick add, indent, outdent and move work as in LML projects. A requirement's number is its short name; a requirement under another requirement is nested in it.
Requirements written in the Editor in that package appear in the document.
Remove deletes a requirement of the package after a confirmation. To take it out without deleting it, move it to another package in the Editor.
Sections stay Holarch items.
Blocks: RTM, RVTM, VCRM, flow-down and allocation matrix blocks list the model's requirements. Live values and live tables read model elements; Kind, Type, Multiplicity and Value (with units, such as 1650 [kg]) are attributes and columns. Insert → Diagram Picture… lists the model's views.
Word, Excel, CSV and Markdown exports contain them.

See Documents for the full reference.

Whiteboards

Whiteboards link to model elements: a card shows the element, and the inspector opens beside the board.

Command	Result
Convert to Model…	Creates requirements, verification cases, parts and actions in the model (other classes stay Holarch items). Lines between them become `satisfy`, `verify`, `allocate` or `dependency` relationships.
Harvest Requirements…	Adds requirement usages to a document (in its package) or to a package of the model.
Generate Diagram…	Moves the linked actions or parts into a new action or part, adds successions (or a connection per line) and opens an Action Flow or Interconnection View of it.

Each command is one undo step, and the notes link to the new elements. See Whiteboards.

DoDAF and UAF

DoDAF and UAF work as in LML projects: the same catalog, products, Architecture Description, Check Architecture and exports, built from the SysML v2 model.

Diagram products are views

Product	View
OV-2, SV-1, SV-2, connectivity views	Interconnection View
OV-5b, SV-4b, combined OV-5b/OV-6c and SV-4/SV-10c, process views	Action Flow View
OV-6c, SV-10c	Sequence View
OV-6b, SV-10b	State Transition View
CV-1, CV-2, OV-4, OV-5a, SV-4a, DIV products, taxonomy and structure views	General View

In + New DoDAF Product or + New UAF View, choose an existing view of that kind, or the package or definition a new view shows. A new view is a view usage in the model.
Timeline products (CV-3, PV-2, SV-8, SV-9, SvcV-8, SvcV-9), radar charts, parametric diagrams and the risk matrix have no SysML v2 view. Their page says what to use instead.
OV-1 and CV-1 can also be an imported picture or a whiteboard. Hotspots link to model elements.

Resource flows

OV-3, SV-6 and SvcV-6 have a part or part definition as their root. The table lists the connections, interfaces and item flows between its parts, and the item flows between actions its parts perform, with the item each one carries.
SV-3 shows the root's parts against each other, with the number of connections between each pair.

Framework concepts as metadata

SysML v2 has no capability, operational activity, performer, system, service, organization, project, standard or measure concept of its own. Holarch uses metadata for them:

The package HolarchFrameworks holds one metadata def per concept.
An element carries a concept as @HolarchFrameworks::Capability; in its body, as #Capability before it, or as metadata Capability about Vehicles::Car; in any package.
Tag Elements… on the DoDAF page and on matrix products adds or removes these tags. It creates the package on first use.
Matrix products (CV-4 to CV-7, PV-1, PV-3, SV-5a, SV-5b, SV-7, SvcV-3a, SvcV-3b, SvcV-5, SvcV-7) take their rows and columns from the tagged elements. Clicking a cell adds or removes an allocate (for performed by) or a dependency.
StdV-1 and StdV-2 list the elements tagged Standard.

Other tools read these tags as plain SysML v2 metadata. See Frameworks for the full reference.

Labels, assignees, comments and history

Select any element (in a view, the Browser or a list) to open the SysML v2 inspector. Its sections are Item, Features, Trace, Discussion and Details.

To see an element on its own page, open its Entity View: click a link to it, double-click it on a Spider or Hierarchy Diagram, choose Open Entity View in a diagram's or the Browser's menu, or pick it in ⌘K / Ctrl+K. The page has the same sections; the top bar has History…, Open in ▾ and More ▾ (Show in Text, Copy Link, Delete Element…). Lock, Duplicate and Children ▾ are LML-only: the text holds the structure.

Feature	Where	Notes
Labels	Item section	Holarch data next to the model.
Assignee, Due date	Item section	My Work lists the elements assigned to you.
Discussion	Discussion section	Comments with @mentions, Resolve and delete. Comments written in the model (`comment about x /* … */`) show above them as "Comment in the model".
History…	Details section	Each recorded change of the element, with before and after values. Revert to version N undoes the later changes to its fields in one step.
Copy link	Details section	Copies a link to the element.
Open in ▾	Inspector head	Text, Browser, each view that shows the element, the Simulator, and the Spider, Hierarchy, Tree, FFBD and IDEF0 diagrams where they apply.

Search

Press ⌘K / Ctrl+K to search. It finds model elements by name, short name, qualified name (Vehicles::Car::battery) and documentation text, plus Holarch items, documents, views and whiteboards. Choosing an element opens it in the Browser.

Collaboration

Shared projects work in SysML v2 projects as in LML projects: the same sharing, roles, live editing and earlier versions. See Collaboration.

Edits by others arrive live in the text, the views and the pages.
When the model changes while you are typing in the Editor, Holarch merges the changes. If both edits touch the same member, a banner says "<package> changed while you were typing." Choose Keep Mine or Take Theirs.
People with view access see the text read-only. People with the Reviewer role can approve and reject requirements.

Ask AI

On the Individual and Team plans, and with your own or your organization's key, Ask AI answers questions about the open SysML v2 model. It reads only the elements a question needs, and the panel says so: "Ask AI reads only the elements a question needs. Changes it proposes open for review first."

Ask about the model: "Which requirements are not satisfied yet?" or "What does the Vehicle part contain?"
Ask about problems: "Which errors does the model have?"
Ask for a change: "Add a doc comment to the engine part." The proposed change opens for review; nothing changes until you apply it, as one undo step. A change that would add errors is refused.

On the Free / Academic plan, Ask AI answers questions about SysML v2 and about using Holarch from Help and Docs, and does not read the model: "Ask AI answers from Help and Docs. Questions about this model need the Individual or Team plan."

How model questions count. Included AI answers model questions with Claude Opus and counts them by size: every 10,000 tokens (the text Claude reads and writes, about 7,500 words) used by model questions in a month counts as one request, rounded up. A short question about a small model counts as one request; a question that reads a large part of a large model can count as several. Questions answered with your own key or your organization's key do not count. See Included AI.

Limits

Not yet available in SysML v2 projects:

State machine simulation.
Editing the language: the standard library is read-only.
Writing to Holarch through the Systems Modeling API: other tools read the current model only.

Also not available for model elements: Change Class, Duplicate, Lock, Copy with Children, and the JSON and .inno exports of model elements.

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