Impact of Design Patterns on Quantitative Assessment of Quality Parameters

Software engineering concept emphasizes on the use of design patterns for developing software which are recurring in nature. The aim of this work is to provide a methodology to compare the quality attributes of a system having design pattern solution with a system without usages of design pattern solution, both the system intending to provide same functionalities. Further, QMOOD (Quality Model for Object-Oriented Design) approach is adopted to assess the effects of design patterns in an object-oriented system environment. Using this approach, object-oriented metrics are calculated in terms of the number of classes and their relationships in a UML (Unified Modeling Language) class diagram. The cut-off points are calculated in order to provide the exact size of the system in terms of the number of classes, for which the solution adopted using design pattern provides more quality parameters. For the demonstration of this approach, different design patterns, such as Visitor, Bridge, and Abstract Factory design patterns have been taken into consideration.