Resources
SDMN 1.0
Structured Data Model and Notation 1.0
SDMN (Shared Data Model and Notation) is a new OMG standard for creating a single, authoritative source of truth for your business data. It was designed to solve the critical problem of data being defined inconsistently across separate BPMN, DMN, and CMMN models. The core principle is “define once, reuse everywhere,” allowing you to build a central library of shared data definitions. Your process, decision, and case models then simply reference these items instead of recreating them. This ensures absolute data consistency and dramatically simplifies maintenance for seamless automation.
What is SDMN and Why Was It Created?
SDMN (Shared Data Model and Notation) is a new, emerging standard from the Object Management Group (OMG). While still in its beta phase, it is designed to be the fourth pillar in the OMG’s business automation suite, logically complementing the “triple crown” of BPMN (for processes), DMN (for decisions), and CMMN (for cases).
So, why was it created? Before SDMN, a significant challenge existed: data definitions were often siloed. A “Customer” data structure might be defined one way as a Data Object in a BPMN process, then slightly differently as an Input Data for a DMN decision, and perhaps again as a Case File Item in CMMN. This led to inconsistency, redundancy, and complex maintenance.
SDMN aims to solve this problem by introducing a standardized way to define and share data models across all other notations. It provides a single, authoritative source of truth for business data structures, ensuring that every process, decision, and case in your organization speaks the same data language.
How Does SDMN Ensure Consistency Across BPMN, DMN, and CMMN?
The core principle of SDMN is “define once, reuse everywhere.” It externalizes data definitions from the individual process, decision, and case models into a central, reusable library.
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Centralized Data Library: SDMN allows you to create a repository of shared data models. Here, you define the structure, attributes, data types, and constraints for key business concepts like “Customer,” “Invoice,” or “Insurance Claim.”
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Elimination of Redundancy: Instead of re-creating these structures in every model, BPMN, DMN, and CMMN models simply reference the definitions from the central SDMN library.
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Simplified Maintenance: When a data structure needs to be changed (e.g., adding a new “VAT Number” field to an invoice), the update is made only once in the central SDMN model. This change is then automatically propagated to every process, decision, and case that uses it, dramatically reducing effort and eliminating the risk of inconsistent updates.
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Improved Business-IT Collaboration on Data: SDMN provides a clear, visual notation for data, allowing business analysts and IT data architects to collaborate on a single, shared understanding of the organization’s data landscape.
What are the Core Components of an SDMN Model?
While the standard is still in beta, its purpose implies a focus on the fundamental building blocks of data modeling, presented in a clear, standardized notation.
Key Elements in an SDMN Model:
Item Definitions: This is the most fundamental element. An Item Definition specifies a distinct business data type, such as a “Customer.”
Structures: Within an Item Definition, you define its structure. This includes its attributes (e.g.,
firstName,lastName,customerID), the specific data type for each attribute (e.g., Text, Number, Date), and any constraints (e.g.,customerIDmust be a 5-digit number).Enumerations: Allows for defining a list of permissible values for an attribute, for example, a “Customer Status” could be an enumeration of “Bronze,” “Silver,” and “Gold.”
Relationships and Associations: SDMN provides ways to define how different Item Definitions relate to each other. For instance, you could model that one “Customer” can have many “Orders,” establishing a clear relationship between the two data structures.
Reusability and Composition: A key feature is the ability to compose complex structures from simpler ones. An “Address” Item Definition could be created once and then reused within both the “Customer” and “Supplier” models.
How Does SDMN Work in Practice with the Other Standards?
The practical workflow enabled by SDMN creates a much more robust and efficient modeling environment.
Model the Data First (or Centrally): Using SDMN, data architects and business analysts collaborate to define the canonical data models for the organization’s key business entities.
Reference from BPMN: When a process modeler creates a BPMN diagram, instead of defining a new data structure for a Data Object, they simply import or reference the “Invoice” definition from the SDMN library.
Reference from DMN: A decision modeler building a DMN table that needs to evaluate an invoice simply references the same shared “Invoice” definition for its Input Data. They can be 100% confident it has the exact same structure as the one used in the BPMN process.
Reference from CMMN: Similarly, a case manager designing a CMMN case plan for handling invoice disputes would add a Case File Item that directly references the official “Invoice” definition from the SDMN library.
This integration ensures seamless, error-free data flow between processes, decisions, and cases.
