Quantifying Quality of Software Design to Measure the Impact of Refactoring

Software design plays a vital role in a software system. A flexible, maintainable, extensible, and re-usable software design enables easier integration of new requirements. In the current era of software development, refactoring is used periodically to fine-tune a software design. Refactoring limits technical debt and improves overall quality of a software design. However, providing a quantitative measure to estimate the impact of a refactoring exercise on a software design is a non-trivial challenge. In this paper, we present a method to estimate the quality (extendibility, and flexibility aspects) of a software design. The method proposes an index namely Software Design Quality Index (SDQI) to estimate the quality of a software design. The index can be employed to measure the impact of a refactoring exercise on software design. Moreover, the method can be used to benchmark and compare software design quality of different software systems.