Mapping Business Scenarios to the Right Notation

When the process is repeatable, follow a clear path—use BPMN. When it’s adaptive, knowledge-driven, and unfolds differently per case—use CMMN.

After two decades of modeling real-world workflows across finance, healthcare, and manufacturing, I’ve learned one truth: the right notation isn’t about preference—it’s about fit. This chapter is your practical, experience-based guide to matching business scenarios to the correct modeling language.

You’ll learn to assess predictability, actor control, and data dependency through real examples. No theory for theory’s sake—just actionable criteria you can apply today.

Key Factors in Notation Selection

Predictability of the Process Flow

BPMN excels when the sequence of steps is consistent across all instances. You know what happens next. Think automated approvals, order fulfillment, or invoice processing.

CMMN shines when the next step depends on the case’s unique context. For example, an insurance claim investigation may require different evidence gathering based on the claim type and severity.

Ask yourself: Is the flow determined by rules or by human judgment? If judgment dominates, CMMN likely fits better.

Who Controls the Workflow?

When the process is triggered and managed by a system or predefined role—BPMN is often the better fit. For instance, a loan application routed through automated credit checks and underwriting rules.

When knowledge workers (e.g., investigators, doctors, legal experts) determine the next steps based on facts, documents, or evolving insight—CMMN is more appropriate. The human is in control, not the workflow.

Data Complexity and Case File Dependencies

BPMN assumes data flows along a structured path—inputs, outputs, and intermediate states are mapped in a predictable way.

CMMN captures the entire case as a container for data: documents, evidence, decisions, and external references. This fits scenarios like incident investigations, legal cases, or patient care plans where data accumulates dynamically.

If your process must track evolving evidence and decisions over time, CMMN’s case file is designed for that.

Decision Framework: Choose BPMN or CMMN

Use this checklist to guide your modeling choice. Apply it to any business scenario you’re modeling.

• Do steps always follow the same sequence? → Yes → Consider BPMN.
• Do exceptions or ad hoc decisions frequently alter the path? → Yes → Consider CMMN.
• Is the outcome determined by a predefined logic engine? → Yes → BPMN.
• Is the outcome shaped by human expertise and evolving facts? → Yes → CMMN.
• Are roles and responsibilities static and assigned in advance? → Yes → BPMN.
• Do roles adapt based on case progress and available expertise? → Yes → CMMN.

When in doubt, ask: Would the same workflow run the same way every time? If yes, BPMN. If no, CMMN.

Real-World Scenarios: BPMN vs CMMN in Action

Scenario 1: Customer Onboarding (Standardized)

For a bank onboarding a new retail customer, the steps are always: identity verification, KYC checks, account creation, and welcome email.

These steps are predictable, repeatable, and governed by compliance rules. BPMN captures this flow cleanly with events, gateways, and automated tasks.

Use BPMN when the process is rules-based, highly automated, and follows a fixed path.

Scenario 2: Insurance Claim Investigation (Adaptive)

Each claim is unique. A car accident may require police reports, repair estimates, witness statements, medical records, and photo evidence.

Some claims escalate to fraud investigation; others are settled quickly. The next step depends on evidence, not a fixed sequence.

CMMN models this through stages (Investigation, Review, Settlement), tasks (gather evidence, consult expert), and decision points based on what’s available.

This is where BPMN fails—because it enforces a rigid flow. CMMN embraces uncertainty.

Scenario 3: Incident Management Across Teams

An IT outage triggers a response. The initial steps are standard: alert, assign, diagnose. But the fix path depends on root cause: software bug, hardware failure, or network issue.

Some incidents require legal reporting, others need customer communication. The workflow diverges based on findings.

Best modeled as a BPMN process for the initial response, but the investigation itself—where facts emerge and decisions unfold—belongs in a CMMN case plan.

Hybrid modeling here ensures automation where possible, flexibility where needed.

When to Use Each: A Quick Comparison

Factor	BPMN	CMMN
Best for	Structured, repeatable workflows	Adaptive, knowledge-driven processes
Flow control	Sequence flow (rigid)	Constraint-based (flexible)
Decision logic	Gateways (exclusive, parallel)	Entry/exit criteria, sentries
Human role	Assigned in advance	Adapts to case needs
Data management	Flow-focused	Case file-centric

Remember: BPMN is about sequence. CMMN is about constraint and control.

Choosing the right notation isn’t just about diagrams—it’s about modeling reality. A rigid BPMN model for a case that unfolds differently every time leads to confusion, resistance, and wasted effort.

And a CMMN model for a predictable process with no variation? It’s overkill and harder to validate.

Use the process modeling decision guide above to make your choice with confidence. This framework has been tested across dozens of projects—dozens of real implementations.

Frequently Asked Questions

Can I use both BPMN and CMMN in the same project?

Absolutely. Many organizations use BPMN for standard operations and CMMN for exception handling or complex cases. Use BPMN to manage the main workflow and embed CMMN as a subprocess for adaptive tasks.

How do I decide whether to use BPMN or CMMN for a process with both structured and unstructured steps?

Break it down. Use BPMN for the predictable parts—like approvals, validations, or system integrations. Use CMMN for the parts that depend on evidence, judgment, or changing facts—like investigation, medical diagnosis, or legal case review.

Is CMMN harder to learn than BPMN?

Not inherently. CMMN’s concepts—stages, tasks, sentries—are intuitive once you understand the mindset. But it requires a shift from flow-centric thinking to constraint-based thinking. With practice and real examples, most analysts adapt quickly.

Can a BPMN model be converted to CMMN—or vice versa?

Not automatically. But you can reframe a BPMN subprocess as a CMMN case when it involves unpredictable steps. For example, a BPMN process for “Customer Support Resolution” can be replaced with a CMMN case if resolution depends on diagnosis, evidence, and expert input.

What tools support both BPMN and CMMN for hybrid modeling?

Visual Paradigm, Camunda, and IBM BPM support both. These tools let you embed CMMN case plans inside BPMN processes or vice versa. Use them to maintain consistency and traceability across models.

Does using CMMN mean I lose automation?

No. CMMN supports automation through event triggers, sentry conditions, and task automation. The difference is that automation is conditional and adaptive—triggered by facts, not fixed sequence. It’s automation with judgment.

Trust the data. Follow the workflow. Choose BPMN or CMMN based on where the real complexity lies—not on convention, not on what’s trendy.

Use this guide to make decisions that reflect reality. That’s how you build models people can actually use.