# Constraint Rules Engine and product configuration flows

*Revenue Management Consultant Study Guide · Configure, Price, Quote · Last updated October 29, 2026 · https://www.certifyforce.com/study-guide/revenue-management-consultant/configure-price-quote/constraint-rules-engine-and-product-configuration-flows*

When to use Constraint Rules Engine instead of Business Rules Engine, how to set it up, which Visual Builder rule type fits a requirement, how the Visual Builder and CML Editor share one constraint model, how reps validate configurations at run time, and how product configuration flows are assigned.

- Certification: Salesforce Revenue Management Consultant
- Exam section: Configure, Price, Quote
- Study guide: https://www.certifyforce.com/study-guide/revenue-management-consultant

**Official exam objective:**

> Use the Product Configurator tool to customize the components and attributes of a product and validate the configuration.

## What the exam expects

- Choose between Business Rules Engine and Constraint Rules Engine, and set up Constraint Rules Engine with its transaction processing type.
- Pick the Visual Builder rule type (constraint, preference, dynamic message, require, exclude, hide/disable) for a requirement.
- Explain how the Visual Builder and the CML Editor share one constraint model, and how Business Rules Engine rules move to CML.
- Turn on Product Validation so reps' configurations are validated as they change.
- Create, default and assign product configuration flows, including multilevel bundles.

Key terms: **Constraint Rules Engine** (configurator engine that runs constraint models); **Constraint Modeling Language (CML)** (language that defines constraint models); **Constraint Builder** (tool holding the Visual Builder and the CML Editor); **preference rule** (soft constraint the engine can override); **product configuration flow** (flow that lays out the configurator for a product or classification).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Constraint Rules Engine toggle | Set Up Configuration Rules and Constraints with Constraints Engine | [Enable Constraint Rules Engine](https://help.salesforce.com/s/articleView?id=ind.product_configurator_set_up_advanced_configurator.htm&language=en_US&type=5) |
| Engine value | AdvancedConfigurator; becomes the default automatically | [Transaction Processing Types](https://help.salesforce.com/s/articleView?id=ind.product_configurator_specify_which_rule_engine_to_use.htm&language=en_US&type=5) |
| Not available | Government Cloud and EU Operating Zone orgs | [Enable Constraint Rules Engine](https://help.salesforce.com/s/articleView?id=ind.product_configurator_set_up_advanced_configurator.htm&language=en_US&type=5) |
| Setup and model access | Product Configuration Constraints Designer permission set | [CML Editor](https://help.salesforce.com/s/articleView?id=ind.product_configurator_use_the_cml_editor.htm&language=en_US&type=5) |
| Business Rules Engine rules after enabling | No longer execute, per the CML guide | [Constraint Modeling Language](https://developer.salesforce.com/docs/revenue/revenue-management/guide/cml-what-is-constraint-modeling-language.html) |
| Message mandatory | Dynamic message rule | [Constraint and Rule Types](https://help.salesforce.com/s/articleView?id=ind.product_configurator_visual_builder_constraint_and_rule_types.htm&language=en_US&type=5) |
| Model limits | 6MB per model; 10 seconds maximum constraint execution | [Product Configurator Limits](https://help.salesforce.com/s/articleView?id=ind.product_configurator_limits.htm&language=en_US&type=5) |
| Product Validation on | Validation rules run on every product selection change | [Validate Product Configuration](https://help.salesforce.com/s/articleView?id=ind.product_configurator_product_validation_enable.htm&language=en_US&type=5) |
| Flow assignment | Active flows only; one flow per product or classification | [Define Product Configuration Flows](https://help.salesforce.com/s/articleView?id=ind.product_configurator_create_a_product_configuration_flow.htm&language=en_US&type=5) |
| Unassigned products | Use the Default flow | [Define Product Configuration Flows](https://help.salesforce.com/s/articleView?id=ind.product_configurator_create_a_product_configuration_flow.htm&language=en_US&type=5) |

## Check yourself

- Why do the CML developer guide and the Help engine table seem to disagree about Business Rules Engine rules?
- What size and time limits apply to constraint models?
- When does a message persist after a Business Rules Engine rule is converted to CML?
- Why must grouping logic with mixed operators use parentheses?

## Sources

- [Rules and Constraints in Configurator With Constraint Rules Engine](https://help.salesforce.com/s/articleView?id=ind.product_configurator_advanced.htm&language=en_US&type=5)
- [Enable Constraint Rules Engine and Create Transaction Processing Types](https://help.salesforce.com/s/articleView?id=ind.product_configurator_set_up_advanced_configurator.htm&language=en_US&type=5)
- [Define Rules Engine with Transaction Processing Types](https://help.salesforce.com/s/articleView?id=ind.product_configurator_specify_which_rule_engine_to_use.htm&language=en_US&type=5)
- [Constraint Modeling Language (Developer Guide)](https://developer.salesforce.com/docs/revenue/revenue-management/guide/cml-what-is-constraint-modeling-language.html)
- [Constraint and Rule Types in the Visual Builder](https://help.salesforce.com/s/articleView?id=ind.product_configurator_visual_builder_constraint_and_rule_types.htm&language=en_US&type=5)
- [Use Code to Define Constraints and Rules in the CML Editor](https://help.salesforce.com/s/articleView?id=ind.product_configurator_use_the_cml_editor.htm&language=en_US&type=5)
- [Convert Rules from Business Rules Engine into CML Code](https://help.salesforce.com/s/articleView?id=ind.product_configurator_convert_bre_rules_to_cml.htm&language=en_US&type=5)
- [Validate Product Configuration](https://help.salesforce.com/s/articleView?id=ind.product_configurator_product_validation_enable.htm&language=en_US&type=5)
- [Define Product Configuration Flows](https://help.salesforce.com/s/articleView?id=ind.product_configurator_create_a_product_configuration_flow.htm&language=en_US&type=5)
- [Product Configurator Limits](https://help.salesforce.com/s/articleView?id=ind.product_configurator_limits.htm&language=en_US&type=5)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 7 linked practice questions, and unlimited timed mock exams are included with the Revenue Management Consultant pack (USD $19): https://www.certifyforce.com/practice-exams