Two-phase model-based testing is an advanced approach in test automation that integrates test design to enhance efficiency and effectiveness. This method involves creating a high-level model to generate abstract test cases that validate requirements early in the software development lifecycle, thereby catching bugs and misunderstandings before implementation. The second phase involves generating low-level test cases, often using a Gherkin-like description, during manual execution, which informs automated code generation for various programming languages. This approach addresses challenges of traditional model-based testing, such as the need for implementation details and coding, by using stateless and stateful models to detect bugs. It adheres to the DRY principle, reducing repetitive test execution, and allows testers to focus on test design without requiring coding expertise. Developed by István Forgács, this method, which emphasizes a shift-left strategy, is designed to be efficient and user-friendly, providing a defect prevention mechanism that doesn't necessitate pre-calculation of results, making it a practical solution for testers.