MAC

BPMN, CMMN and DMN engines in one Flowable deployment.

MAC is a workflow platform for the Canada Revenue Agency, built on one Flowable 6.6 deployment. Coordinators run ordered processes, case workers pick up work as the case allows, and decision tables settle the branches, tasks are assigned to real people through the agency’s existing SSO.

BPMN + CMMN + DMN in one Spring Boot deployment
Kerberos identity bridged into the engine’s identity context
Documents in PostgreSQL via the ContentStorage SPI

Key terms

BPMN: Business Process Model and Notation: ordered process definitions

CMMN: Case Management Model and Notation: case work with no fixed order

DMN: Decision Model and Notation: decision tables evaluated as rules

Flowable: The open-source engine providing all three runtimes, embedded here at 6.6

IDM: Flowable’s identity module: user and group queries, backed by the directory

SPNEGO: The HTTP negotiation that carries a Kerberos ticket on each request

Architecture

One WAR on JBoss/WildFly carries the Angular assets, the Spring Boot server and all three embedded engines. As lead developer, I built the seam around Flowable: filters that give it an identity, resource subclasses that expose runtime state to the front end, and a storage implementation that keeps documents in the database.

CRA staff

Domain-joined workstations, no separate login

HTTPS / SPNEGO

One WAR on JBoss/WildFly

mac-web

Angular 16 on Angular Material and the CRA RCCR component libraries

Task inboxTask detailStart formsBPMN viewerCMMN viewer

JSON over /mac/api

mac-server

Spring Boot WAR, Java 8, JPA/Hibernate: the code MAC owns is the seam around Flowable

SpnegoHttpFilterAuthenticatedUserFilterCustomDiagramResourceDatabaseContentStorageRestApiInterceptor

Embedded engine APIs

Flowable 6.6

BPMN engine

Ordered processes

CMMN engine

Case work

DMN engine

Decision tables

One JDBC connection pool

PostgreSQL

One schema holding engine runtime state, full history and ContentItem document bytes

Outside the boundary

Kerberos KDC

SPNEGO

Ticket validation on every request

Active Directory

LDAP

Backs the Flowable IDM user query

SMTP relay

SMTP

Task and escalation notifications

Three engines in one deployment gives one transaction boundary and one identity context, so a case can start a process and read a decision result without a distributed commit. The cost is that BPMN, CMMN and DMN share a Flowable version and a schema migration, and upgrade together or not at all.

Decisions

BPMN, CMMN and DMN engines share one Spring Boot context, one transaction boundary and one identity.

Line of thinking

The work is genuinely three shapes: ordered processes, case work where the order is the worker’s, and rules the business changes without a release. Three services would have meant three deployments and a distributed commit every time a case started a process. Embedding all three engines in one context gives a single transaction and a single inbox over all of them. The cost is coupling their upgrade cycles: one Flowable version and one schema migration for all three, so none of them moves alone.

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Orchestrates long-running work across BPMN processes, CMMN case work and DMN decision tables in one Flowable 6.6 deployment. The agency’s existing SSO identity names who holds each task, and the engine records every transition. Spring Boot on JBoss/WildFly, Angular front end, PostgreSQL.