"UML Tutorial: Part 1" has explored a few of the notational elements that UML supplies for static soft- ware design. In future columns this article will expand upon this notation by showing how to use it for solving some real software problems. | UML Tutorial: Part 1 -- Class Diagrams. Robert C. Martin My next several columns will be a running tutorial of UML. The version of UML was released on the 13th of January, 1997. The release should be out before the end of the year. This column will track the progress of UML and present the issues that the three amigos (Grady Booch, Jim Rumbaugh, and Ivar Jacobson) are dealing with. Introduction UML stands for Unified Modeling Language. It represents a unification of the concepts and notations presented by the three amigos in their respective books1. The goal is for UML to become a common language for creating models of object oriented computer software. In its current form UML is comprised of two major components: a Meta-model and a notation. In the future, some form of method or process may also be added to; or associated with, UML. The Meta-model UML is unique in that it has a standard data representation. This representation is called the metamodel. The meta-model is a description of UML in UML. It describes the objects, attributes, and relationships necessary to represent the concepts of UML within a software application. This provides CASE manufacturers with a standard and unambiguous way to represent UML models. Hopefully it will allow for easy transport of UML models between tools. It may also make it easier to write ancillary tools for browsing, summarizing, and modifying UML models. A deeper discussion of the metamodel is beyond the scope of this column. Interested readers can learn more about it by downloading the UML documents from the rational web site2. The Notation The UML notation is rich and full bodied. It is comprised of two major subdivisions. There is a notation for modeling the static elements of a design such as classes, attributes, and relationships. There is also a notation for modeling the dynamic elements of a design such as objects, messages, and finite state machines. In this article we will present some of the aspects of the static