https://jjcit.org/paper/134 10.5455/jjcit.71-1616087318 Abdelkareem M. Alashqar Software engineering,Object-oriented,UML,Use cases,Scenarios,Natural language processing 14 7960 2002 18-Mar.-2021 9-May-2021 and 19-May-2021 22-May-2021 Effective software modeling tools are necessary for successful achievement of software engineering activities, especially when working in the analysis and design phase. Automating these tools facilitates work, makes it more productive and reduces cost and time of development. This paper aims at the development and validation of a method and a software tool for automatic generation of UML diagrams when following the approach of object- oriented development. These diagrams are generated from scenario-based requirements in order to facilitate the modeling process. So, a template of scenario-based requirements and its components are identified and constructed. Then a method including an algorithm is designed and implemented based on natural language processing (NLP) to generate UML diagrams automatically from the scenario-based requirements. The diagrams include sequence and class diagrams. The ability, performance and benefits of the proposed method and the software tool are reported by experimental results.