RBV—Rule-Based Verification—is a mechanism for verifying the syntax of Business Process Model and Notation (BPMN) diagrams by applying logical rules and is available as an additional feature of the Bee-Up modeling tool. Business Process Model and Notation (BPMN) is a widely used, standardized method for graphically representing the steps in a business process. Ensuring the syntactic correctness of BPMN models is crucial for their effective execution and interpretation. However, manually verifying large and complex BPMN models can be time-consuming and error-prone. The intention of this project is to provide Bee-Up modelers with an automated and user-friendly mechanism for detecting and highlighting any issues that cause diagrams to deviate from the official rules of the standard while also serving as a foundation for further implementations and optimizations. The same approach could be applied to create various controls for the other types of diagrams supported by Bee-Up. For the realization of the aforementioned controls, interaction between the modeling tool and a rule engine is required. This chapter presents the set of technical components and explains how each contributes to the final implementation. Additionally, the related features are outlined.