Why knowledge graphs stall after the initial prototype
Entity slides and a graph visualisation are not a production system. Without disciplined ontology scope, automated validation contracts, and a retrieval architecture that respects structure and permissions, knowledge graphs quickly become expensive catalogues that nobody trusts.
1. Ontology and knowledge-graph modelling
Start with the concrete queries, compliance checks, and write/update paths your system must support—not with the largest possible domain schema. Establish stable identifiers, explicit relation types, and clear ownership of who may assert facts. Version your vocabulary and treat silent renames as breaking changes.
2. SHACL vs JSON Schema
Use JSON Schema when payloads are document-shaped APIs and hierarchical trees. Use SHACL when constraints span graph neighbourhoods, typed links, and RDF or knowledge-graph stores. Production architectures frequently combine both: JSON Schema at the API ingress edge, and SHACL on the graph of record.
3. GraphRAG vs vector-only RAG
Vector-only RAG is usually sufficient for unstructured prose lookup. GraphRAG (or hybrid graph + vector retrieval) pays off when answers require multi-hop relationships, strict entity disambiguation, or governance over which facts may be cited. Do not maintain a graph solely to decorate vector embeddings.
4. Reasoning and inference engines
Introduce OWL, rule engines, or SHACL-based inference when derived facts genuinely reduce duplicate maintenance—and when your team can test and explain every derivation. Skip heavyweight reasoners when closed-world SHACL validation already enforces the business policy you need.
Practice FAQ
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Do we need a formal OWL ontology before building GraphRAG?
You need a deliberate entity and relationship model with stable IDs; full OWL formalisation is optional until automated inference or cross-organisation vocabularies require it.
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Should we implement SHACL or JSON Schema first?
Match the shape of your data plane—validate incoming documents with JSON Schema at the API boundary, and add SHACL where multi-entity links and graph invariants matter.
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When does external implementation support make sense?
When schema validation, IAM-aware retrieval citations, and ontology governance need to ship together in production rather as disconnected prototypes.
Knowledge-graph delivery with Devolute
We scope ontology design, SHACL/JSON Schema contracts, GraphRAG, and reasoning with clear engineering deliverables.
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