Prediction model for bug re-opens in Mozilla Firefox Prabhdeep Kaur * Department of Computer Engineering, Baba Banda Singh Bahadur Polytechnic College Fatehgarh Sahib,Punjab,India Puneet Mittal 2 Department of Computer Science and Engineering, Baba Banda Singh Bahadur Engineering College Fatehgarh Sahib,Punjab,India Amandeep Singh 3 Department of Computer Engineering, Baba Banda Singh Bahadur Polytechnic College Fatehgarh Sahib,Punjab,India Abstract: - Bug fixing becomes the most crucial activity in the software development process. Fixing bugs accounts a large amount of time of software development task. Sometimes these bug fixes are incomplete or inappropriate and results in bug reopen. Reopened bugs degrades the overall quality of the software perceived by the users and also increases the maintenance costs and indicates instability in the software system. Bugs can be re-opened for a variety of reasons. In this paper, we determined that which factors indicate whether a bug will be re-opened or not using Bugzilla database for Mozilla Firefox. An analysis is performed on components, different severity levels and the last resolution for the trunk version and Unspecified version of Mozilla Firefox to study their impact on bug re-opens. A relationship between significant factors is also established to make the prediction model more accurate. The findings of this work contribute towards better understanding of what factors impact bug re-openings so they can be examined more carefully. Keywords: - Bug re-open, Component, Severity, Last Resolution. I INTRODUCTION Every developer wants to develop software which is free from errors or bugs. But as a man-made artifact, software suffers from various software bugs, which cause crashes, hangs or incorrect results and significantly threaten the reliability and also the security of computer systems. Software Quality cannot be improved without knowledge of development process. The number of bugs and errors occurred during the software development process have to be found in the early stages of development for better quality. Bugs are detected either during testing before release or in the field by customers post-release. Once a bug is discovered, developers usually need to fix it. In particular, for bugs that have direct, severe impact on customers, vendors usually make releasing timely patches the highest priority in order to minimize the amount of system down time [29]. Unfortunately, fixes to bugs are not bullet proof since they are also written by human. Some fixes either do not fix the problem completely or even introduce new problems. Mistakes in bug fixes may be caused by many possible reasons. First, bug fixing is usually under very tight time schedule, typically with deadlines in days or even hours, definitely not weeks. Such time pressure can cause fixers to have much less time to think cautiously, especially about the potential side-effects and the interaction with the rest of the system. Similarly, such time pressure prevents testers from conducting thorough regression tests before releasing the fix. Second, bug fixing usually has a narrow focus (e.g., removing the bug) comparing to general development. As such, the fixer regards fixing the target bug as the sole objective and accomplishment to be evaluated by his/her manager. Therefore, he/she would pay much more attention to the bug itself than the correctness of the rest of the system [29]. Bug reopening is of vital interest to the software developers in order to • Improve the quality of bug fixing process • Identify important issues that are not fixed and later result in bug reopens • Identifying factors that influence the likelihood of a bug being re-opened • Minimize the occurrence of re-opened bugs. Prabhdeep Kaur et al. / International Journal of Computer Science & Engineering Technology (IJCSET) ISSN : 2229-3345 Vol. 6 No. 07 Jul 2015 399