Object-oriented concepts are crucial in software design because they address fundamental issues of adaptation and evolution. With the proliferation of object-oriented notations and methods, the Unified Modeling Language (UML) has emerged to provide a standardized notation for describing object-oriented models. However, for the UML notation to be effectively applied, it needs to be used with an object-oriented analysis and design method. This tutorial describes the COMET method for designing real-time and distributed applications, which integrates object-oriented and concurrency concepts and uses the UML notation.