Open Property Data Association
Smart Property Data Trust Framework
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    Project roadmap — semantic modelling + governance

    Concrete deliverables, sequenced. The discovery phase is done; this is what we produce from here.

    What's already done (discovery phase)

    • 5 GitHub repos cloned with full history
    • 86-page WordPress site mirror + 6-page Astro site mirror
    • 40+ video transcripts (YouTube, Vimeo, SharePoint Stream)
    • 119 SharePoint documents organised into taxonomy
    • Full UK government initiative mapped (this docs site)
    • Governance framework choice settled (ToIP, evidenced from OPDA's own publications)

    Phase 1 — Foundations (next 2–3 weeks)

    Foundation

    Read the Statement of Work

    source/00-deliverables/Draft Statement of Work - schema.docx — anchors everything else; tells us what Maria has formally scoped.

    Foundation

    Plan + roadmap document

    source/00-deliverables/plan.md and roadmap.md — synthesise this knowledge base plus the SoW into a single project plan.

    Foundation

    Merged glossary v0.1

    Reconcile trust-framework-poc/Glossary.xlsx + working-groups/technical/Glossary.xlsx + JSON Schema property names. Single source of truth for terminology.

    Foundation

    Stakeholder map

    Who, what they need, when. Driven by the departments, steering forums pages and member list.

    Phase 2 — Semantic model v0.1 (weeks 3–6)

    Modelling

    Concept taxonomy (SKOS)

    Top-level categories derived from pdtf-transaction.json v3. Output: 00-deliverables/semantic-models/taxonomy.ttl + .md human-readable view.

    Modelling

    Data dictionary

    Every data element with definition, type, source, ownership. Auto-extracted from JSON Schema then enriched.

    Modelling

    Ontology skeleton (OWL/Turtle)

    Core classes only: Transaction, Property, Participant, Claim, Document, Search, Listing, Form. Reuse W3C VC, Schema.org, FOAF/ORG, GeoSPARQL.

    Modelling

    First mapping spec

    JSON Schema → JSON-LD context → RDF. Pick one overlay (BASPI v5) end-to-end as the worked example.

    Phase 3 — Governance documents (weeks 4–8, overlapping)

    Per ToIP, working through the four layers + cross-cutting docs. Each starts from existing OPDA artefacts (in source/03-standards/trust-framework/docs/) and adds the structure that's missing.

    1. L4 Ecosystem Governance Framework (consolidates existing governance.md, plan.md, proposal.md, etc.)
    2. L3 Credential Trust Framework (SPDTF VC spec + issuer rules)
    3. L2 Communication Governance (HTTPS profile, DIDComm version, security audit cadence)
    4. L1 Utility Governance (DID methods allowed, trust-registry data structures, key rotation)
    5. Conformance & Certification scheme (Open Banking-style)
    6. Risk & Liability allocation
    7. Disputes & Redress process

    Phase 4 — Presentations for stakeholders (weeks 6–10)

    Three core decks for OPDA's stakeholder engagement:

    • Approach deck — why linked data, why ToIP, why now
    • Governance deck — the framework, the documents, the operating model
    • Technology deck — JSON Schema → JSON-LD → SHACL → OWL → DID/VC pipeline

    Phase sequence

    flowchart LR subgraph P1["`Phase 1 — Foundations *2 weeks*`"] direction TB p1a["`Read SoW + synthesis 3d`"]:::neutral p1b["`Plan + roadmap doc 4d`"]:::neutral p1c["`Merged glossary v0.1 7d`"]:::neutral p1d["`Stakeholder map 5d`"]:::neutral p1a --> p1b p1a --> p1c p1a --> p1d end subgraph P2["`Phase 2 — Semantic model *3 weeks*`"] direction TB p2a["`Concept taxonomy SKOS · 7d`"]:::neutral p2b["`Data dictionary 10d`"]:::neutral p2c["`Ontology skeleton OWL · 7d`"]:::neutral p2d["`First mapping BASPI v5 · 7d`"]:::neutral p2a --> p2c p2c --> p2d end subgraph P3["`Phase 3 — Governance docs *5 weeks*`"] direction TB p3a["`L4 Ecosystem doc 14d`"]:::neutral p3b["`L3 Credential trust fw 10d`"]:::neutral p3c["`L2 Comms governance 7d`"]:::neutral p3d["`L1 Utility governance 7d`"]:::neutral p3e["`Conformance scheme 14d`"]:::neutral p3a --> p3b p3a --> p3c p3a --> p3d p3a --> p3e end subgraph P4["`Phase 4 — Presentations *2 weeks*`"] direction TB p4a["`Approach deck 10d`"]:::neutral p4b["`Governance deck 10d`"]:::neutral p4c["`Technology deck 10d`"]:::neutral end class P1,P2,P3,P4 infra; %% Cross-phase dependencies p1c --> p2a p1c --> p2b p1b --> p3a p1b --> p4a p3a --> p4b p2c --> p4c
    Phase sequence with cross-phase dependencies. Each task box shows duration in days; arrows show what blocks what.

    External dependencies

    DependencyWhat we needOwner
    Maria's SoW formalisationScope sign-off on the above planOPDA Chair
    MHCLG material-information replacement guidanceDefinitive successor to NTS — affects nts.json overlay futureMHCLG (Oct 2025 consultation)
    DPMSG working-group decisionsSeveral pending decisions on the PDTF schema v3.6 and the collaboratively authored SPDTF scheme draftDPMSG Technical WG
    Raidiam infrastructure specTrust registry data modelRaidiam (Sandbox partner)
    BASPI v5 finalisationHBSG release of BASPI v5HBSG

    Risks & watch-items

    Watch out
    • NTS overlay drift — nts.json implements withdrawn guidance. Needs explicit retirement/replacement plan once MHCLG publishes successor.
    • Two glossaries — Technical WG and Trust Framework PoC both have Glossary.xlsx. May contain conflicting definitions.
    • Schema v3 vs v3.6 vs v2 coexistence — multiple versions live in repos and dependencies. Need clear sunset dates. The recommended mitigation is transition-bridging tooling (current→new schema bridges plus implementation tooling for industry) so members can migrate without a hard cut-over.
    • Transition-tooling funding — the bridging tooling and industry implementation tooling above need delivery resource. The funding / resource requirement should be surfaced to the stakeholder, since existing project funding may have scope to cover it. Tracked as item F7 in the deferred-work register.
    • Open Banking-style funding — long-run sustainability of OPDA isn't settled. Cost-recovery participant fees model worth proposing in governance docs.
    • Government department reorganisations — DLUHC → MHCLG; DCMS → DSIT. Names change; relationships need to be person-resilient.

    Success criteria

    By end of phase 3 (≈ week 8), OPDA can:

    • Point to a complete published governance framework, layered per ToIP, citing each existing artefact.
    • Walk a stakeholder through a JSON property data instance, its RDF projection, and the SHACL constraints it must satisfy.
    • Show how every UK government initiative tier maps to OPDA's standards stack.
    • Hand a new DPMSG working-group member a single reading list that brings them up to speed in < 1 day.

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