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Universal Hospitality Domain Model

Foundation Paper
Mike Adams – October 17, 2025

Purpose and vision

The Universal Hospitality Domain Model (UHDM) is an independent research project to define a shared conceptual model for the hospitality industry.

Its goal is to establish a neutral, universal vocabulary that helps developers, integrators, and analysts communicate clearly, design interoperable systems, and avoid re-inventing the same structures across different platforms.

The UHDM is vendor-neutral and technology-neutral. It focuses on the semantics of hospitality — the language of rooms, rates, guests, reservations, and services — rather than on specific API or message formats.

In an era increasingly shaped by AI-driven reasoning and machine understanding, such a shared domain language has become more than a technical convenience: it’s the foundation for meaningful interoperability. Emerging frameworks such as the Model Context Protocol (MCP) demonstrate how structured, shared semantics can empower AI systems to interpret and act on real-world data consistently — precisely the kind of alignment UHDM seeks to provide within hospitality.

Ultimately, UHDM aims to make the digital hospitality ecosystem more coherent, connected, and comprehensible, providing a foundation for the next generation of interoperable software.

This is a personal project by Mike Adams, shared openly in the hope that it contributes value to the wider hospitality technology community. Once the foundations are established, contributions and collaboration will be welcomed.

Scope

No model can be truly universal. UHDM begins from a hospitality-centric, PMS-oriented, and data-driven perspective — focusing on the conceptual backbone of hotel and lodging operations.

It seeks to cover key systems such as PMS, RMS, POS, booking engines, and related integrations — the operational layer that underpins the hospitality ecosystem.

Why this matters

Hospitality technology remains highly fragmented. Thousands of systems — from PMSs, RMSs and CRSs, to POS, upsell platforms, door locks, accounting systems and more — attempt to describe the same operational reality in incompatible ways.

Each vendor defines its own semantics: what is a room, a rate, a reservation? Without a shared domain language, even the best APIs are built on shifting sand.

Past standardization efforts have helped, but haven’t solved this core issue:

  • HTNG and OpenTravel Alliance (OTA) achieved valuable progress but focused largely on message-level standards (XML/SOAP/JSON) rather than conceptual models.
  • These standards often became tied to specific technologies that aged poorly.
  • Participation was typically limited to large vendors; smaller players lacked representation.
  • As a result, the integration problem remains — particularly on the operational side of hospitality.

UHDM takes a different approach: semantic unification before technical standardization. Once the concepts and relationships are right, APIs and schemas can evolve naturally with technology.

Relationship to existing standards

The UHDM initiative does not aim to replace efforts by OpenTravel, HTNG/AHLA, or broader foundations such as Overture Maps.

Instead, it seeks to complement these standards by providing a conceptual framework — a language that can sit beneath or alongside them.

Where Schema.org provides a general schema for web content, UHDM aims to provide a deeper and more operational model specific to hospitality systems.

The intent is to produce something that others — including standards bodies — can adopt, extend, or formalize if useful.

Approach

The UHDM methodology involves:

  1. Reverse-engineering existing hospitality PMS APIs and schemas to extract common business concepts.
  2. Comparing and correlating these models to identify core entities and relationships.
  3. Formalizing those into a unified, technology-agnostic domain model.
  4. Translating that model into a structured ontology and schema (e.g. JSON-LD), suitable for use in interoperability, integration, and AI contexts.

The model is designed to be ontology-driven, layered, and extensible — capable of evolving as new systems and data domains emerge.

Value proposition

For hotels: Lower integration costs, faster partner onboarding, and greater flexibility in vendor choice.
For software vendors: Simplified partner integrations, reduced support burden, and faster time-to-market.
For consultants and developers: Reusable templates and semantic frameworks that make integration predictable.
For the ecosystem as a whole: A step toward genuine interoperability — essential for innovation in AI, analytics, and guest experience.

Next steps

The next major milestone will follow a phase of reverse-engineering leading PMS APIs, after which the first unified conceptual model — the initial domain definition for UHDM — will be published.

Future deliverables may include:

  • Visual domain model diagrams
  • A structured ontology and schema (JSON-LD or GraphQL)
  • Mapping guides between systems
  • Reference links to schema.org and other ontologies

Contact

Mike Adams
LinkedIn: linkedin.com/in/mikeadamsprofessional
Email: mike@myglassesaredirty.com

This document is shared under an open license to encourage discussion and collaboration. The author welcomes feedback and contribution from all interested members of the hospitality technology community.