Conceptual data model
CDQ's conceptual data model is the business view of the master data that CDQ services validate, match, enrich and monitor. It groups that data into 5 domains with 37 entities, The domains are Business Partner, Payment, Product, Location and Certificate. The Reference Domain Object Model (RDOM), CDQ's technical standard for how its services structure and name the data, realizes them with its 501 concepts.
Domains and entities
Each domain is built around one main entity, such as the bank account in Payment, and models its own entities with their attributes, relationships and value sets. Each domain page shows the entities of the domain in a diagram of their own.
Scope and design principles
The model is conceptual, SAP-aligned and minimal: it holds only the entities and relationships that have a clear link to a data quality rule or to external reference data. It is not an enterprise data model, an SAP data model or an ERP schema. It is organized in 5 domains, the 37 entities within them, and the attributes, relationships and value sets that describe each entity (Elements of the conceptual level).
Ten design principles decide what enters the model and where it sits. An entity or attribute that fails one of them stays out, even when SAP has a field for it.
Each domain models its own entities
There is no shared layer of concepts or entities. Each domain models the entities it needs explicitly. Identifier in Business Partner and Product Identifier in Product, for example, are separate entity types. The similarity is accepted on purpose: they have different issuers, rules and reference data, so modelling them separately is precision, not redundancy. Merging them into one generic entity would lose meaning.
This follows conceptual modelling, which models entity types as they are[1][2], ISO/IEC 11179, where the object class determines what a property means[3], and Domain-Driven Design, which accepts similar concepts in different contexts[4]. The real risk is drift, the same idea modelled inconsistently across domains. Design principle 5 is the rule against it.
Source, Evidence, Assessment, Finding, Event and Case are not part of this model either. They are what CDQ's services produce about records (provenance, results and follow-up), belong to the capability side and refer to records of the five domains. Design principle 7 means they must not be mixed into domain entities, not that this model defines them.
What is not a domain
Validation, matching, enrichment, monitoring, compliance, fraud prevention and data sharing are capabilities: they act on entities and their records and are never domains.
| Candidate | Decision | Why |
|---|---|---|
| Risk, compliance, fraud | Capabilities producing Assessments and Findings | They evaluate records from several domains. An entity does not become a risk entity because a risk service evaluates its records. The findings, assessments and evidence these services produce refer to records of the five domains but are not part of this model. |
| Transaction | Evidence only | An open purchase order or payment matters only as evidence behind a finding, never as an entity to master. |
| Contract | Entity in Business Partner | Its identity comes from its parties. |
| Asset | Excluded | Its defining data is organization-specific with no external reference data. Its verifiable aspects are covered by Product, Location, Business Partner and Certificate. |
Industry scenarios
Ten standard situations from CDQ's main industries (machinery, logistics, retail, chemistry and pharma) walked through the entities and relationships of the model. Each card shows the path through the model, what CDQ checks along it, and how the model handles the case. Read each path from left to right, in the direction of the relationships. Small text in brackets gives the role or an example.
All ten scenarios run on existing entities. Transactions such as sales orders and shipments appear only as evidence, and decisions such as export licences are capabilities. Three refinements follow from them:
- Business Relationship needs "brand of", "franchise" and "legal successor" besides ownership and hierarchy. The relation types in the RDOM are hierarchy-oriented today (for example
DIRECT_LEGAL_RELATIONandCOMMERCIAL_ULTIMATE), so the value set is extended in the conceptual model first. - Product Partner Relationship applies to Product as well as Material. Manufacturer and brand owner are facts about the canonical product, supplier and customer are the client's view.
- Certificate Scope stays simple. One certificate with several scopes covers a company and its sites, and each scope has exactly one subject.
Material → has → Product Partner Relationship (manufacturer, supplier) → with → Business Partner
Product → spare part of → Product (the machine)
Business Partner (customer) → acts as → Contract Party
Business Partner → uses → Address (delivery) → within → Administrative Area (country)
Business Partner → has → Tax Registration (VAT)
Business Partner → has → Legal Form
Business Partner → has → Business Partner Status
Business Partner → holds → Account Holder Relationship → for → Bank Account → verified by → Account Verification
Location → has → Geolocation
Business Partner → uses → Address (invoicing, PO box)
Material → has → Product Partner Relationship (supplier, brand owner) → with → Business Partner
Business Partner (franchisee) → franchise of → Business Relationship → to → Business Partner (brand owner)
Business Partner (franchisee) → operates → Site (store) → located at → Location → has → Address
Material → represents → Product
Material → has → Product Partner Relationship (supplier) → with → Business Partner
Product → classified as → Product Classification (dangerous goods)
Certificate → issued by → Issuer → is a → Business Partner (authority, certification body)
Material → has → Material Site Assignment → at → Site
Certificate → has → Certificate Scope → covers → Site (warehouse)
Business Partner → operates → Site
Certificate → issued by → Issuer → is a → Business Partner (authority)
Material → has → Product Partner Relationship (manufacturer) → with → Business Partner → operates → Site
Certificate (GMP) → has → Certificate Scope → covers → Site
Product → originates in → Administrative Area (country)
Foundations
The model sits at the top of a three-level stack. The conceptual data model gives the business view of what the data means. RDOM is the logical model beneath it, the technical standard by which APIs, databases and indexes name and structure the data. The implementation level, called the physical level in the modelling literature, is how each service puts RDOM into practice. Each level realizes the one above it, so the business view can be documented and refined without changing RDOM or any system.
| Level | What it describes | At CDQ | Changes when |
|---|---|---|---|
| Conceptual | What the data means in business terms: entity types, relationships and constraints, without technical structure | This model: domains, entities, attributes, relationships and value sets (Elements of the conceptual level) | CDQ's understanding of the business changes |
| Logical | How the data is structured, named and typed, independent of a particular database or interface | RDOM, the centrally managed OpenAPI schemas (Reference Domain Object Model) | A new service or field is standardized |
| Implementation | How each system actually stores, indexes and transmits the data | API payloads, databases, search indexes and stores inside each service, designed according to RDOM | Storage, performance or interface needs change |
Elements of the conceptual level
On meta.cdq.com every element of the model is called a concept, in line with ISO/IEC 11179[3]. On the conceptual level these concepts are of five kinds. RDOM realizes them as schema objects, fields and enumerations, and the implementations as tables, columns, index fields and payload properties.
| Element | Meaning | Example | On meta.cdq.com |
|---|---|---|---|
| Domain | A family of entities with their own identity and reference data | Payment | Grouping of root concepts |
| Entity | Short for entity type[1][2]: a kind of thing the business deals with, not a single occurrence. A single occurrence is a record, and matching, monitoring and sharing work on records. An entity that relates other entities and carries attributes of its own, such as Account Holder Relationship, is an associative entity. | Bank Account. One specific bank account is a record. | Root or node concept |
| Attribute | A property of an entity | IBAN | Leaf concept |
| Relationship | A typed link between entities, with cardinality | Bank Account is held at a Financial Institution | Relation |
| Value set | The allowed values of an attribute, the conceptual domain of ISO/IEC 11179[3] | Account status: active, closed | Type concept |
Where the levels come from
The idea of separate levels linked by mappings goes back to the three-schema architecture of the ANSI/X3/SPARC Study Group on Database Management Systems[5], formalised in ISO/TR 9007[2]. Its middle level, the conceptual schema, was meant as the single description of the enterprise's data, but it mixed business meaning with technical structure. Kent[6] proposed splitting it in two, a part that describes the enterprise and a part that describes the data structures. That split is the conceptual and logical level used in practice today. CDQ's setup follows it exactly: the conceptual data model is the business half, RDOM the logical half. RDOM's role across all services is also what integration architecture calls a canonical data model[7].
Why "conceptual data model"
In the standards the business-facing level is the conceptual schema[5][2]. The research field calls the discipline conceptual modelling[8], with its own conference since 1979, today the International Conference on Conceptual Modeling. "Conceptual data model" is the established practitioner term for this level and the counterpart of "logical data model", the role RDOM plays, so the pair is self-explaining.
The alternatives carry baggage. "Data model" alone is ambiguous next to RDOM, which is a data model too. "Domain model" collides with Domain-Driven Design, where a domain means something else than a data domain. "Ontology" implies formal logic and reasoning the model does not claim. "Semantic model" is read today as a layer of business intelligence tools.
How the foundations shape the model
| Foundation | What it means here |
|---|---|
| Entity-relationship notation | Entities, relationships and cardinalities in the diagrams follow Chen's entity-relationship model[1], the original notation for the conceptual level. |
| 100 % principle | ISO/TR 9007[2] requires every relevant aspect of the universe of discourse in the conceptual schema. Here the universe of discourse is what CDQ services act on. Principle 1 decides what is relevant, and that is then modelled here and nowhere else. |
| Conceptualization principle | The conceptual level holds only conceptually relevant aspects, without data representation, physical organisation or access paths[2]. Principles 6 and 10 apply it: SAP structures and RDOM field layouts never shape the business view. |
| Concepts and their realizations | ISO/IEC 11179[3] separates a data element concept (an object class with a property) from a data element (the concept with a representation). Concepts on meta.cdq.com are the former, and RDOM fields are the latter. |
The same layering in practice
| Standard | How it layers |
|---|---|
| ISO 20022, financial messaging | The standard's metamodel defines a conceptual, a logical and a physical level with traceability from one to the next. Business components are modelled once and realized in message definitions and syntaxes such as XML and JSON[9]. |
| EU Core Vocabularies | Core Business, Core Person and Core Location are deliberately minimal conceptual models of a legal entity, a person and a location. Application profiles and technical representations are derived from them under the SEMIC style guide's separation of concerns[10]. |
| UN/CEFACT core components | Syntax-neutral core components form the conceptual layer of B2B document standards such as UBL. Business information entities and XML bindings realize them in context, standardized as ISO 15000-5[11]. |
Not everyone shares one model. Domain-Driven Design[4] holds that a model is consistent only within a bounded context and warns against enterprise-wide canonical models. CDQ's setup is compatible with that critique: RDOM is canonical within one bounded context, CDQ's own services, and principle 1 keeps the conceptual model to what those services act on. OMG's Model Driven Architecture names the same three levels differently, as computation-independent, platform-independent and platform-specific model[12].
References
- ↑ 1.0 1.1 1.2 P. P. Chen: The Entity-Relationship Model — Toward a Unified View of Data. ACM Transactions on Database Systems 1(1), 9–36, 1976. doi:10.1145/320434.320440
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 ISO/TR 9007:1987 Information processing systems — Concepts and terminology for the conceptual schema and the information base (ed. J. J. van Griethuysen); last reviewed and confirmed 2022. iso.org
- ↑ 3.0 3.1 3.2 3.3 ISO/IEC 11179 Information technology — Metadata registries (MDR), in particular Part 3 (registry metamodel) and Part 31:2023 (metamodel for data specification registration: data element concepts, object classes, properties).
- ↑ 4.0 4.1 E. Evans: Domain-Driven Design: Tackling Complexity in the Heart of Software. Addison-Wesley, 2003.
- ↑ 5.0 5.1 D. Tsichritzis, A. Klug (eds.): The ANSI/X3/SPARC DBMS Framework. Report of the Study Group on Database Management Systems. Information Systems 3(3), 173–191, 1978. Journal issue
- ↑ W. Kent: Splitting the Conceptual Schema. Proceedings of the 6th International Conference on Very Large Data Bases (VLDB), 10–14, 1980. VLDB record
- ↑ G. Hohpe, B. Woolf: Enterprise Integration Patterns, pattern "Canonical Data Model". Addison-Wesley, 2003.
- ↑ A. Olivé: Conceptual Modeling of Information Systems. Springer, 2007.
- ↑ ISO 20022-1 Financial services — Universal financial industry message scheme — Part 1: Metamodel, clauses on the conceptual, logical and physical level and the mappings between them (2013, new edition 2026). Preview of ISO 20022-1:2026
- ↑ European Commission, SEMIC: Core Vocabularies (Core Business, Core Person, Core Location, Core Public Organisation) and the SEMIC Style Guide for semantic data specifications. Specifications · Style guide
- ↑ UN/CEFACT: Core Components Technical Specification 3.0 and ISO 15000-5:2014 Electronic Business Extensible Markup Language (ebXML) — Part 5: Core Components Specification. CCTS 3.0 overview
- ↑ Object Management Group: MDA Guide rev. 2.0, 2014 (computation-independent, platform-independent and platform-specific models).