Following are some of the main advantages of Use Case Modeling:
1. The use case diagram provides a comprehensive summary of the whole software system in a single illustration.
2. The use cases are mainly composed of narrative text. Hence, unlike many other modeling techniques, the non technical stake holders (e.g. customers, end users, salesperson etc) are also able understand the model for the software system. This means that feedback can be obtained at a very early stage of the development from the customers and the end users.
3. Another major advantage of use case modeling is that it requires the identification of exceptional scenarios for the use cases. This helps in discovering subtle alternate requirements in the system.
4. The use case model can be utilized in several other aspect of software development as well, e.g. Cost Estimation, Project Planning, Test Case Preparation and User Documentation.
Click below link to see Use Case Diagram