Several Issues on the Definition of Algorithm for the Layout of the UML Class Diagrams

System modeling is one of the important tasks to be solved during software development. As more complex software systems become as higher requirements are defined for demonstrative presentation of the system to be developed. To solve this task the main attention is devoted to the transparency of the model elements within the graphical presentation of the system. The paper defines the classification of different types of UML diagrams, which are created during development of the software system. This classification is based on the different combinations of nodes and arcs of the diagram graph. The UML class diagram is selected for deeper analysis to the elements' layout. Authors offer to use main principles of the genetic algorithm to automate the replacement of the diagram created in the manual way. Current results are quite theoretical yet and authors will continue the research based on the issues defined in this paper.