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Guide Origin: Community

/arckit-nl:nl-gemma maps a gemeente's application landscape onto GEMMA (Gemeentelijke Model Architectuur, VNG Realisatie): the referentiecomponenten its applications fill, the bedrijfsfuncties they support, the standards and data exchange GEMMA expects between them, and where the landscape falls short. The result is a set of roadmap candidates, each traced to a finding. It describes what applications are used for. It never calls a product "GEMMA-compliant" and never recommends products or suppliers; product information belongs in the GEMMA Softwarecatalogus.

See also: Netherlands overlay guide · NORA conformance guide

Inputs

Artefact Purpose
GEMMA referentiecomponenten extract (projects/000-global/external/gemma-referentiecomponenten.md) Mandatory. Components, applicatieservices, groups, standards and data exchange, built by the overlay's nl-references.py from the GEMMA Archi-repository. Without it the command stops and writes nothing.
GEMMA bedrijfsfunctiemodel extract (gemma-bedrijfsfuncties.md) Optional. Needed for bedrijfsfunctie coverage (Section 4); without it that section is skipped and the gap noted.
GEMMA principles extract (gemma-principes.md) Optional. Lets roadmap candidates name the GAP principle they serve.
A landscape source Mandatory. In order of strength: an explicit mapping (a GEMMA Softwarecatalogus export, the gemeente's ArchiMate model, an inventory with a GEMMA column), an application inventory (ARC-<id>-APP, from /arckit-togaf-adm:application-inventory in the TOGAF ADM overlay), other application lists, plates or contract registers in external/, or applications named in the input. Without any, the command stops and says which would help.
Architecture principles (ARC-000-PRIN-v1.0.md) Recommended. Portfolio, standardisation, reuse and cloud principles
Requirements (ARC-<id>-REQ-v1.0.md) Recommended. Required capabilities and integrations, when the scope is one project
Data model, diagrams Recommended. Integrations and data flows, as evidence for data exchange
NORA assessment, roadmap, capability map, risk register Optional. Read when present

Command

/arckit-nl:nl-gemma <project ID or scope>

In Claude Code the overlay installs as its own plugin, arckit-nl, so the command is /arckit-nl:nl-gemma.

Example: /arckit-nl:nl-gemma Map the full application landscape of the gemeente for 001, using the ArchiMate extract in 000-global/external

Output: projects/<id>/ARC-<id>-GEMMA-v1.0.md. A re-run writes the next version beside the earlier one.

The command first runs nl-references.py gemma to fetch or refresh the extracts. The overlay guide explains the statuses, offline builds from a downloaded GEMMA release.xml, and extracts placed by hand. A manual or offline status is recorded under Source limitations.

How the Landscape Is Mapped

  1. Each application is mapped to one or more referentiecomponenten, using only names that appear in the extract, with a confidence:
    • Stated — a source links the application to the component explicitly; the source is cited.
    • Inferred — derived from the application's described purpose and the component's description and applicatieservices; a one-line rationale is given. Most landscapes have no explicit mapping, so most mappings are Inferred, and the summary shows the split.
    • Unmapped — no component fits, and none is forced.
  2. Coverage lists the filled components, with an overlap flag where several applications fill one, and the unfilled components with a relevance judgement: Expected, Possibly not needed, or To be confirmed (the default). Overlap is examined for sector-specific use before it is called a finding.
  3. Bedrijfsfunctie coverage marks each function in scope Supported, Not supported (a landscape gap), or No GEMMA component (a property of the reference model, not of the landscape).
  4. Standards and data exchange are evidence-based: a standard is Supported, Not supported or Unknown per application, and a GEMMA data exchange between filled components is Present, Absent or Unknown. Unknown is the default; GEMMA linking a standard to a component says nothing about a product.
  5. Roadmap candidates follow from the findings: Rationalise, Fill, Standardise, Integrate, or Replace or keep (with an ADR). Each has a priority with a reason and, when the principles extract is present, the GAP principle it serves.

If the organisation is not a gemeente, the mapping says so prominently: GEMMA is the municipal reference model, and the result is then indicative only.

Deliverable Snapshot

Section Contents
Executive Summary Scope, GEMMA source version, mapping split (Stated / Inferred / Unmapped), coverage figures, key findings
1. Scope and Sources The gemeente and scope, every landscape source with its date, every extract with its source version, Source limitations
2. Application Mapping Each application, its product and supplier as the sources state them, components, confidence and evidence
3. Coverage of Referentiecomponenten Filled components with overlap flags; unfilled components by group, with relevance judgements
4. Bedrijfsfunctie Coverage Supported, Not supported and No GEMMA component per group, with the Not supported functions listed
5. Standards Per filled component, the GEMMA standards and each application's support, with evidence
6. Data Exchange and Buitengemeentelijke Voorzieningen GEMMA data exchange between filled components, and the voorzieningen the landscape connects to
7. Roadmap Candidates Each candidate with its type, the finding it traces to, a priority with a reason, and the GAP principle where available
8. External References Every extract (with the EUPL licence line) and every landscape source in the Document Register

Review Checklist

  • nl-references.py ran first, and a manual or offline status is under Source limitations with the script's note and error.
  • Every component, applicatieservice, bedrijfsfunctie and standard name matches the extract exactly; none is invented, merged or renamed.
  • Every application has a confidence: Stated mappings cite their source, Inferred mappings give a rationale, Unmapped applications are not forced.
  • Overlap is checked for sector-specific use before a rationalisation candidate is proposed.
  • Unfilled components carry a relevance judgement with a reason.
  • Bedrijfsfunctie coverage keeps Not supported (landscape gap) apart from No GEMMA component (reference-model property).
  • Standards and data exchange rest on evidence, with Unknown where there is none.
  • Every roadmap candidate traces to a finding and has a priority with a reason, and no product or supplier is recommended or called GEMMA-compliant.
  • Inferred mappings are validated with the application owners before the mapping is relied on, and the GEMMA text is checked against gemmaonline.nl.

Next Steps

  • /arckit:roadmap — turn the roadmap candidates into a sequenced architecture roadmap.
  • /arckit-nl:nl-nora — assess NORA and GEMMA principle conformance; this mapping is evidence for the reuse and standardisation principles.
  • /arckit:adr — record decisions on overlapping applications, and on unmapped applications that will be kept.
  • /arckit:principles — reflect GEMMA alignment in the organisation's architecture principles if they do not reference it yet.