Design Assessment Indicator for Object Oriented Software

Abstract

Object-oriented paradigm emerged and attracted increasing support throughout the software engineering profession and also provided the definition of new classes of objects that inherit much of their behaviour from previously defined classes. It is mostly unclear as what design quality really is involved in constructing a design that confines the requirements and limitation necessary to be used. Even qualified professionals may never become expert designers. All professionals learn strategies and techniques for improving their design approaches through applying values, extensive experience, opinion and lessons learned from other designers. Software design is an essential cost driver in software development, it not only causes the cost of its own formation, but it also strongly influences the cost of implementation and maintenance. The design phase takes only 5–10% of the total effort (over the whole software life cycle), but a large part (up to 80%) of the total effort is taken for improving design decisions or structure Even if the initial design is good enough for that moment, there may be difficulties when attempting to make changes and extensions during the maintenance phase. The goal of this work is to develop a model that provides a relevant interpretation of measurement results when applied to the investigation of object-oriented software design. The research proposes a design phase quality model to assess the design of any object-oriented system. The research also focusses on analyzing a set of metrics, which has a direct influence on the quality of the software and creating a design phase tool based on Java that can be used to validate the object-oriented projects against these metrics. For the proposed model, new metrics and some well-known metrics were adopted and validated. The analysis was carried out on a set of real time projects designed using Unified Modeling Language, which were used as test cases. Finally, the model presents valuable indications to the designers to validate their quality of software design. The design assessment indicator can also help to compare the design alternatives by evaluating each alternative and comparing its results.