The native Public Sector design combines an OmniScript application form with Business Rules Engine . Salesforce explicitly documents this architecture for automatically calculating processing fees associated with business license applications. Business Rules Engine uses Decision Matrices and Expression Sets to determine fee amounts from multiple input criteria, while the OmniScript captures those constituent inputs.

For example, a Decision Matrix can contain base-fee values indexed by authorization type, industry category, location, revenue band, or another applicable parameter. An Expression Set invokes one or more matrices, performs any additional arithmetic, and returns a calculated currency amount. Salesforce documents that Expression Sets and Decision Matrices accept JSON input from and return JSON output to OmniScripts.

The integration is direct: Salesforce explains that an Expression Set Action can be added to the OmniScript so that, when the applicant supplies the required information, the Business Rules Engine processes those values and returns the appropriate license fee.

Triggered Flow could calculate values, but it would duplicate a purpose-built policy calculation engine. Integration Procedures are appropriate for data orchestration and external integrations, not for replacing BRE as the authoritative fee-policy engine. A generic Flow application also bypasses the Public Sector OmniScript application architecture.

Study Guide Reference: Public Sector Solution Product Configuration – OmniScripts; Business Rules Engine; Expression Sets; Decision Matrices; automated application fee calculation.

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