Data-Driven Application Maintenance: Views from the Trenches

In this paper we present our experience during design, development, and pilot deployments of a data-driven machine learning based application maintenance solution. We implemented a proof of concept to address a spectrum of interrelated problems encountered in application maintenance projects including duplicate incident ticket identification, assignee recommendation, theme mining, and mapping of incidents to business processes. In the context of IT services, these problems are frequently encountered, yet there is a gap in bringing automation and optimization. Despite long-standing research around mining and analysis of software repositories, such research outputs are not adopted well in practice due to the constraints these solutions impose on the users. We discuss need for designing pragmatic solutions with low barriers to adoption and addressing right level of complexity of problems with respect to underlying business constraints and nature of data.Comment: Earlier version of paper appearing in proceedings of the 4th International Workshop on Software Engineering Research and Industrial Practice (SER&IP), IEEE Press, pp. 48-54, 201

Characterizing and Predicting Blocking Bugs in Open Source Projects

Software engineering researchers have studied specific types of issues such reopened bugs, performance bugs, dormant bugs, etc. However, one special type of severe bugs is blocking bugs. Blocking bugs are software bugs that prevent other bugs from being fixed. These bugs may increase maintenance costs, reduce overall quality and delay the release of the software systems. In this paper, we study blocking bugs in eight open source projects and propose a model to predict them early on. We extract 14 different factors (from the bug repositories) that are made available within 24 hours after the initial submission of the bug reports. Then, we build decision trees to predict whether a bug will be a blocking bugs or not. Our results show that our prediction models achieve F-measures of 21%-54%, which is a two-fold improvement over the baseline predictors. We also analyze the fixes of these blocking bugs to understand their negative impact. We find that fixing blocking bugs requires more lines of code to be touched compared to non-blocking bugs. In addition, our file-level analysis shows that files affected by blocking bugs are more negatively impacted in terms of cohesion, coupling complexity and size than files affected by non-blocking bugs

Categorizing and predicting reopened bug reports to improve software reliability

Software maintenance takes two thirds of the life cycle of the project. Bug fixes are an important part of software maintenance. Bugs are tracked using online tools like Bugzilla. It has been noted that around 10% of fixes are buggy fixes. Many bugs are documented as fixed when they are not actually fixed, thus reducing the reliability of the software. The overlooked bugs are critical as they take more resources to fix when discovered, and since they are not documented, the reality is that defect are still present and reduce reliability of software. There have been very few studies in understanding these bugs. The best way to understand these bugs is to mine software repositories. To generalize findings we need a large number of bug information and a wide category of software projects. To solve the problem, a web crawler collected around a million bug reports from online repositories, and extracted important attributes of the bug reports. We selected four algorithms: Bayesian network, NaiveBayes, C4.5 decision tree, and Alternating decision tree. We achieved a decent amount of accuracy in predicting reopened bugs across a wide range of projects. Using AdaBoost, we analyzed the most important factors responsible for the bugs and categorized them in three categories of reputation of committer, complex units, and insufficient knowledge of defect

Understanding the Impact of Diversity in Software Bugs on Bug Prediction Models

Nowadays, software systems are essential for businesses, users and society. At the same time such systems are growing both in complexity and size. In this context, developing high-quality software is a challenging and expensive activity for the software industry. Since software organizations are always limited by their budget, personnel and time, it is not a trivial task to allocate testing and code-review resources to areas that require the most attention. To overcome the above problem, researchers have developed software bug prediction models that can help practitioners to predict the most bug-prone software entities. Although, software bug prediction is a very popular research area, yet its industrial adoption remains limited. In this thesis, we investigate three possible issues with the current state-of-the-art in software bug prediction that affect the practical usability of prediction models. First, we argue that current bug prediction models implicitly assume that all bugs are the same without taking into consideration their impact. We study the impact of bugs in terms of experience of the developers required to fix them. Second, only few studies investigate the impact of specific type of bugs. Therefore, we characterize a severe type of bug called Blocking bugs, and provide approaches to predict them early on. Third, false-negative files are buggy files that bug prediction models incorrectly as non-buggy files. We argue that a large number of false-negative files makes bug prediction models less attractive for developers. In our thesis, we quantify the extent of false-negative files, and manually inspect them in order to better understand their nature

Analyze the Performance of Software by Machine Learning Methods for Fault Prediction Techniques

Trend of using the software in daily life is increasing day by day. Software system development is growing more difficult as these technologies are integrated into daily life. Therefore, creating highly effective software is a significant difficulty. The quality of any software system continues to be the most important element among all the required characteristics. Nearly one-third of the total cost of software development goes toward testing. Therefore, it is always advantageous to find a software bug early in the software development process because if it is not found early, it will drive up the cost of the software development. This type of issue is intended to be resolved via software fault prediction. There is always a need for a better and enhanced prediction model in order to forecast the fault before the real testing and so reduce the flaws in the time and expense of software projects. The various machine learning techniques for classifying software bugs are discussed in this paper