This paper shows the development of a CASE tool for UML 2.2 diagrams graph, which we will call Lenny UML 1.0. This tool was built to the need for various companies, which acquire a tool like this is very expensive for the payment of licenses and often find it difficult to handle them or understand them, either by their unfriendly interfaces or the language in which they are located._x000D_ LennyUML is designed for all companies regardless of Peruvian area, allowing them to document their systems with diagrams commonly used in our area such as: Use Case diagram, object diagram, class diagram, state diagrams and activity diagrams. This tool serves as a focus for future updates and / or changes that may occur in the system as per the changing and dynamic nature of software development prevents a system can be fully defined in the specification phase or continuing changes The Subsequent phas...