Refactoring of Code to Remove Technical Debt and Reduce Maintenance Effort

Software development organizations face issue like Technical Debt in their software projects. Technical Debt (TD) is incurred when a person involved in engineering of software, intentionally or unintentionally makes wrong or non-optimal design decisions. This problem occurs due to non-systematic and undefined approach to manage the high level of uncertainty in requirements. These non-optimal design decisions and the nonsystematic approach can result in introduction of code smells. Code smells are actually technical debt (also known as perceived debt), which may cause a project to fade out with time. Code of a software project with technical debt is considered as unclean code. Refactoring is an activity of modifying the code to remove technical debt from a software project and make the project code clean. Goal of this work is to study the impact of removing TD on the effort required to add features and remove bugs from software. To this end, this work uses a stepwise approach; first code smells (considered as TD) are identified, and in the next step the smells are removed and impact of removing the code smells (on removing bug and adding new feature) is observed in terms of effort required during maintenance. Technical debt in five open source software applications has been calculated and impact of removing the code smells has been observed on one of the applications named NopCommerce (an ecommerce-based system). Effort to add a new feature and remove a bug, before and after refactoring, has been calculated in terms of man-hours. The effort required to add new feature and remove a bug from the clean code has been 7% less as compared to the effort required to do the same in unclean code. Whether to perform refactoring or not is a decision made by software developers. The impact of refactoring in reducing effort required to maintain code will help a developer make a decision regarding refactoring.