Standard model

The metamodel that workspace.init writes into a new workspace. A workspace can change it; keys never change.

Types

Need (need)

What a stakeholder needs, in their own words. System requirements derive from needs.

• Short ID prefix: N
• Meaning: need
• Properties: title, rationale, topic, source, source-identifier, import-date, delivery, import-version
• Required: title

Use Case (use-case)

A goal a user reaches with the system, step by step. Requirements can refine it.

• Short ID prefix: UC
• Properties: title, rationale, source, source-identifier, import-date, delivery, import-version
• Required: title

System Requirement (system-requirement)

What the system must do or be, verified against its acceptance criteria.

• Short ID prefix: SR
• Meaning: requirement
• Properties: title, rationale, requirement-type, acceptance-criteria, validity, packages, emergent, verification-method, statement, source, source-identifier, import-date, delivery, import-version, topic
• Required: title, requirement-type, acceptance-criteria

Decision (decision)

A decision with its rationale; requirements are based on it.

• Short ID prefix: D
• Properties: title, rationale, source, source-identifier, import-date, delivery, import-version
• Required: title

Variant (variant)

A variant of the product. Its requirements replace requirements of the core only through Replaces; Excludes names the core requirements that do not apply in it.

• Short ID prefix: VAR
• Meaning: variant
• Properties: title, source, source-identifier, import-date, delivery, import-version
• Required: title

Package (package)

A group of elements. System requirements name it in their property Package.

• Short ID prefix: PKG
• Meaning: package
• Properties: title, source, source-identifier, import-date, delivery, import-version
• Required: title

Properties

Title (title)

Short name of the element, shown with its short ID.

• Kind: text
• Meaning: title

Rationale (rationale)

Why the element exists or is as it is.

• Kind: text
• Markdown text.

Requirement Type (requirement-type)

The kind of requirement.

• Kind: choice
• Choices: Functional (functional), Quality (quality), Performance (performance), Interface (interface), Constraint (constraint)
• Counts to the version of the element.

Acceptance Criteria (acceptance-criteria)

The conditions under which the requirement is met, one per entry.

• Kind: text, several values
• Counts to the version of the element.
• Markdown text.

Validity (validity)

The variants the requirement applies to; without validity it belongs to the core and applies to every variant.

• Kind: relation, several values
• Target types: variant
• Meaning: validity
• Counts to the version of the element.

Package (packages)

The packages the element belongs to.

• Kind: relation, several values
• Target types: package
• Meaning: packages

Emergent (emergent)

Whether the requirement has emergent behaviour: behaviour that does not follow from its children alone. Such a requirement needs evidence of its own.

• Kind: choice
• Choices: Yes (yes), No (no)
• Meaning: emergent

Verification Method (verification-method)

How the requirement is verified.

• Kind: choice
• Choices: Test (test), Analysis (analysis), Inspection (inspection), Demonstration (demonstration)
• Meaning: verification-method

Statement (statement)

The supplier’s statement on an imported requirement, exported to the source with reqif export --statements. It does not count to the version; the requirement itself is the element text.

• Kind: text
• Meaning: statement

Source (source)

The source the element was imported from.

• Kind: text
• Meaning: source

Source Identifier (source-identifier)

The identifier of the element in its source.

• Kind: text
• Meaning: source-identifier

Import Date (import-date)

The date of the import.

• Kind: date
• Meaning: import-date

Delivery (delivery)

The name of the delivery the element was imported from.

• Kind: text
• Meaning: delivery

Import Version (import-version)

The import version: the version of what the import wrote, right after the last import.

• Kind: text
• Meaning: import-version

Topic (topic)

The topic the element belongs to, as the project names its topics.

• Kind: text

Relation kinds

Refines (refines)

The source details the target, for example a requirement a need. A chain follows it from need to requirement.

• Inverse name: Refined by
• Meaning: derivation

Derives from (derives-from)

A system requirement derives from a need, a use case or another system requirement. A chain follows it.

• Inverse name: Derived by
• From types: system-requirement
• To types: need, use-case, system-requirement
• Meaning: derivation

Based on (based-on)

The source is based on a decision.

• Inverse name: Basis for
• To types: decision

Supersedes (supersedes)

The source says that it supersedes the target. Superseding an element (element.supersede) also sets the target to an invalid status; the relation alone does not.

• Inverse name: Superseded by
• Meaning: succession

Replaces (replaces)

A system requirement of a variant replaces one of the core in that variant.

• Inverse name: Replaced by
• From types: system-requirement
• To types: system-requirement
• Meaning: replacement

Excludes (excludes)

A variant excludes a system requirement of the core: it does not apply in that variant.

• Inverse name: Excluded by
• From types: variant
• To types: system-requirement
• Meaning: exclusion

Statuses

Draft (draft)

Being written or changed.

• The status of a new element.

Approved (approved)

Agreed and valid.

Obsolete (obsolete)

No longer valid. The element stays visible in the chain.

• Invalid: the element counts neither for coverage nor for indirect verification.