N-ary Relations of Association in Class Diagrams: Design Patterns

Sergievskiy Maxim

doi:10.14569/ijacsa.2016.070237

Abstract

Most of the technology of object-oriented development relies on the use of UML diagrams, in particular, class diagrams. CASE tools, used for automation of object-oriented development, often do not support n-ary associations in the class diagrams, and their implementation in the form of program code in contrast to binary rather time-consuming. The article will show how in some cases it is possible to move from the n-ary association between classes to binary and how can reduce the number of objects. The rules to transform models, that contain n-ary association, will be presented in the form of design patterns. Proposed three new design patterns can be used in the process of developing software systems. These patterns describe transformations of n-ary (often ternary) associations occur between classes in binary and the introduction of additional classes and binary association with the aim of optimizing the model.

Highlights

As it is known, UML is the standard tool for modeling software systems [1], [2], [3], [4]
At the later stage software system model in the form of a class diagrams will be transformed into a logical database model and object-oriented application code
The article will demonstrate how in some cases it is possible to move from the n-ary association between classes to binary, and how you can reduce the number of potential objects of class-associations

Summary

INTRODUCTION

UML is the standard tool for modeling software systems [1], [2], [3], [4]. The design stage primarily uses class diagrams from the UML. They describe the model of a software system reflecting the main parameters of the subject area. At the later stage software system model in the form of a class diagrams will be transformed into a logical database model and object-oriented application code. The majority of CASE tools do not support n-ary (in particular, ternary) association relationships in the class diagrams [2], [5]. The article will demonstrate how in some cases it is possible to move from the n-ary association between classes (often ternary) to binary, and how you can reduce the number of potential objects of class-associations. Guidelines for the conversion of models containing n-ary association will be shown in the form of design patterns [6]

REPLACING TERNARY ASSOCIATION ON BINARY AND CLASS-ASSOCIATION

REPLACEMENT OF THE N-ARY ASSOCIATION WITH BINARY ONES

CONCLUSION