Resources
CMMN 1.1
Case Management Model and Notation 1.1
CMMN (Case Management Model and Notation) is a standard for modeling dynamic and unpredictable work, known as case management. Unlike the strict, sequential flow of BPMN, CMMN focuses on empowering knowledge workers by defining what actions are available rather than prescribing a rigid path. It uses a declarative, event-driven approach where tasks become active as new information emerges during a case. This makes it ideal for managing complex scenarios like insurance claims, patient treatment, or service requests. In essence, CMMN provides a flexible framework for managing unpredictable, human-driven processes.
What is CMMN and When Should You Use It?
CMMN (Case Management Model and Notation) is the third key standard from the Object Management Group (OMG), designed to work alongside BPMN and DMN. While BPMN excels at modeling structured, predictable processes, CMMN is specifically designed for the opposite: unstructured, unpredictable, and dynamic situations, often called “cases.”
Think of a doctor diagnosing a patient, a team investigating an insurance fraud claim, or an expert handling a complex customer complaint. In these scenarios, there is no rigid, predefined sequence of steps. The next action depends entirely on the evolving context, incoming information, and the judgment of a knowledge worker. CMMN provides the framework to model and manage this type of adaptive, event-driven work.
Its purpose is not to enforce a strict process, but to empower knowledge workers. It provides them with a flexible plan, access to all necessary information, and a set of potential actions they can take to move the case toward a resolution.
How is CMMN Different from BPMN?
Understanding the difference between CMMN and BPMN is crucial for choosing the right tool for the job. It’s a fundamental difference in philosophy:
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BPMN (The Flowchart): BPMN is imperative. It tells you exactly what must happen and in what order. The process controls the flow, and tasks are executed along a predefined path. It’s about efficiency and repeatability in a predictable environment.
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CMMN (The To-Do List & Toolkit): CMMN is declarative. It tells you what is possible at any given moment. The knowledge worker (the case manager) controls the flow, choosing the most appropriate action from a list of available options based on their expertise and the case context. It’s about effectiveness and adaptability in an unpredictable environment.
Trying to force a dynamic case into a rigid BPMN model often leads to overly complex diagrams with dozens of exceptions, while using CMMN for a simple, repeatable process is overkill. The two standards are complementary,
What are the Core Components of a CMMN Model?
A CMMN model is visually represented as a Case Plan, which looks like a folder or a dossier. This “Case File” contains all the elements related to the case.
Key Elements Inside the Case Plan:
Case File Item: Represents the data and information related to the case, such as documents, forms, and data objects. This is the central repository of information for the case worker.
Tasks: These are the actual units of work to be done.
Human Task: An action performed by a case worker.
Process Task: Triggers a structured BPMN process from within the case.
Decision Task: Calls a DMN model to execute a business decision.
Stages: These are like phases or milestones within the case, represented by rectangles with angled corners. A stage can contain its own set of tasks and can be activated or deactivated as the case progresses. They help structure a complex case into manageable parts.
Milestones: Represent significant achievements or deliverables within the case. Reaching a milestone (e.g., “Investigation Complete”) signifies that a certain state has been achieved, which can then trigger new tasks or stages.
Sentries (The “Listeners”): This is the most powerful concept in CMMN. A sentry is the “guard” that watches the state of the case. It is an Event-Condition-Action (ECA) rule.
Event: A trigger occurs (e.g., a document is uploaded).
Condition: A specific condition is met (e.g., the document is an “approved” invoice).
Action: A task or stage becomes available for the case worker.
Sentries, depicted as diamonds on the edge of tasks or stages, are what make the case model dynamic and responsive to events.
How Does the “Three-Headed Monster” of BPMN, DMN, and CMMN Work Together?
The true power of these OMG standards is realized when they are used together to orchestrate all types of work within an enterprise.
A CMMN Case (e.g., “Process Patient Admission”) is initiated to manage an overall, unpredictable situation.
Within the case, the doctor might perform a Human Task (“Initial Examination”).
Based on the exam, the doctor triggers a Process Task that calls a structured BPMN Process (“Run Standard Blood Tests”). This process is predictable and the same for every patient.
The results of the blood test are added to the Case File, triggering a sentry that makes a Decision Task available. This task calls a DMN Model (“Evaluate Health Risk”) to analyze the results against complex rules.
The DMN result (e.g., “High Risk”) is returned to the CMMN case, reaching a Milestone and making a new set of tasks and stages available to the doctor for further, specialized treatment.
This seamless integration allows an organization to use the best model for each part of the job: CMMN for flexibility, BPMN for efficiency, and DMN for intelligence.
