Entity Relationship Diagram Template

An entity relationship diagram template documents the data model of a system: the entities, how they relate, the key strategy behind each one, and the full field specifications with type, nullability, default, index and sensitivity. It lets a team decide the shape of the data before the first migration runs, and lets a security reviewer see which fields hold personal data. Specira generates the entity relationship diagram (ERD) from the named entities and compiles the field tables from the session's typed items and resolved decisions.

A hand-drawn data model stops at the boxes. The diagram shows a Job and a Technician with a line between them, and the questions that matter live nowhere: is the key natural or surrogate, is a null reason code a blank or a meaning, which columns are personal data, and how long positions are kept. Those answers end up decided in a migration file at eleven at night.

What sections does the entity relationship diagram template contain?

The governed default template fixes eight sections. Six are tables built from typed items, one is a generated diagram, and the migration outline is prose synthesized from discovery.

Section	Depth	How it is produced
Entity Inventory	core	Table from typed items · Entity, Description, Approx Row Count
Entity Relationships	core	Generated diagram
Key Fields	core	Table from typed items · Entity, Field, Type, Constraints
Full Field Specifications	standard	Table from typed items · Entity, Field, Type, Nullable, Default, Index
CRUD Matrix	standard	Table from typed items · Entity, Role, Create, Read, Update, Delete
Data Classification Labels	full	Table from typed items · Entity, Field, Classification, PII
Retention Rules	full	Table from typed items · Entity, Retention Period, Archive Strategy
Migration Scripts Outline	full	Prose synthesized from discovery

How does Specira build the data model document?

The Solutions Architect agent owns this artefact. It compiles the document from the entities, business rules, constraints and decisions typed during discovery, with the Security Analyst's classification constraints feeding the sensitivity columns. The sample shows the mechanism. Entity Relationship Views generates one crow's-foot diagram per bounded context from versioned source and reconciles its inventory with the architecture document both ways, so a system-of-record decision is cited there and never re-decided here. Entities, Keys and Conventions states the audit, delete and tenancy conventions once, then gives each entity its primary key strategy and the reason for it, linking business meaning to the glossary. Field Specifications gives every field a type with precision, a stated nullability and default, a sensitivity that cites the governing classification, a source, and a description that adds meaning beyond the name. A blank cell is a gap, and the template flags it.

The Red Team Critic consults on every turn and runs the export readiness gate, measuring resolved decisions rather than pages. A retention rule whose decision is open renders as a named gap, never as a plausible default. Every row carries provenance: who decided, when, on what evidence, and glossary terms from the knowledge base are matched with a confidence score and cited. Export as DOCX for reviewers or as Markdown and JSON for agents, where the schema also travels as a consolidated DBML (database markup language) block. Push to Jira, Confluence, GitHub or Linear, or clone and adjust the template in the Templates module.

First page of the sample: Data Model (ERD and Field Specs)

Rendered sample

Rendered from the Specira governed default template on a fictional company, watermarked, with its diagrams. Read it in the browser or take the PDF.

PDF View online

How do teams use the data model document?

✓
Write the first migrationDevelopers take the field specifications and the migration outline and produce a schema that matches the decisions, not their memory of them.
✓
Run the privacy reviewThe Security Analyst and the privacy officer read the classification labels and retention rules without opening a second document.
✓
Settle the system-of-record questionThe entity inventory cites which system owns each entity, so read copies and transitional markers stay explicit.
✓
Give agents the schema as dataDownstream tooling reads the JSON export and the DBML block instead of parsing a diagram image.

What does the data model artefact look like in Specira?

The screens below show the entities being typed in a discovery session, the generated entity relationship diagram, and the export gate for this artefact.

Specira requirements list with quality scores, sources and two discovery proposals awaiting a decision — **Requirements with quality scores**Fifteen requirements, each with a quality score, source (manual, discovery, AI-suggested) and owner. Two discovery proposals wait for a decision.

Specira Knowledge Base: 68 entries, 90% health, 61 active signals, aging entries flagged — **Knowledge base with health signals**68 entries at 90% average health, 61 active signals, five drafts awaiting review. Aging entries are flagged before an agent relies on them.

Specira discovery session: lead answer with inline agent notes, signals and a knowledge base match — **Discovery session, five agents on one turn**A Solutions Architect answer with two inline agent notes (Solutions Architect, UX Researcher) under it. 7 of 16 signals detected, 30 deliverables active.

Specira export package listing 28 deliverables grouped by Business Analyst, UX Researcher, Solutions Architect and Security Analyst — **Export package: 28 deliverables**The bundle grouped by owning agent: 8 of 8 business analysis, 4 of 4 experience, 9 of 9 architecture, then security and compliance, each deliverable with its page estimate.

Screens are from a seeded Specira demo workspace; counts and scores are sample data.

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What do teams ask about this artefact?

An entity relationship diagram (ERD) template is a structured document that fixes the entities of a system, their relationships and cardinality, the key strategy of each entity, and the full field specifications. Specira's version adds a CRUD (create, read, update, delete) matrix by role, data classification labels, retention rules and a migration outline, all compiled from the same discovery session.

From the named entities and relationships typed in the session. Specira produces one view per bounded context, with crow's-foot cardinality, and embeds it as an image in the export. Past the entity cap a view splits by aggregate rather than shrinking. The diagram carries structure, keys and cardinality; precision, defaults and enumerations live in the field tables, where a diagram cannot express them.

Type with precision, nullability and default stated explicitly, sensitivity citing the governing classification, source (user-entered, system, integration or seed data), and a description that adds meaning beyond the field name. A blank cell counts as a gap. In the sample, a null override reason code is documented as meaning an accepted suggestion, never a blank string.

Yes, both ways. The entity inventory reconciles with the architecture document's data chapter, so an entity present in one and missing from the other is a finding. Decisions such as which system is the system of record are made in the architecture document and cited here, never re-decided, and the cross-reference production strategy keeps the two artefacts pointing at each other.

DOCX for human readers, Markdown and JSON for agents, and a zip per session or project, with pushes to Jira, Confluence, GitHub and Linear. The agent export also carries the schema as a consolidated DBML (database markup language) block beside the tables. The Red Team Critic's export gate lists any deferred decision in the gap report before the file ships.