Change Impact Analysis: A Tool for Effective Regression Testing

Change impact analysis is an imperative activity for the maintenance of software. It determines the set of modules that are changed and modules that are affected by the change(s). It helps in regression testing because only those modules that are either changed or affected by the suggested change(s) are retested. Change impact analysis is a complex activity as it is very difficult to predict the impact of a change in software. Different researchers have proposed different change impact analysis approaches that help in prioritization of test cases for regression testing. In this paper, an approach based on Total Importance of Module (TIM) has been proposed that determines the importance of a module on the basis of (i) user requirements, and (ii) system requirements. The results of the proposed algorithm showed that the importance of a module is an essential attribute in forming a prioritized test suite for regression testing

Modelos de análisis de impacto aplicados a la gestión de riesgos en proyectos de desarrollo de software: una revisión sistemática de la literatura

El análisis de impacto aplicado a un proyecto de desarrollo de software permite determinar entre otros los factores o atributos que se ven afectados de manera positiva o negativa. Los valores de estos atributos como: tiempo, presupuesto y cronograma, entre otros, varían en el tiempo y deben ser controlados por el responsable del proyecto, sin embargo éstos no siempre se apoyan en la gestión de 1s de manera adecuada. El objetivo de este trabajo es identificar modelos de análisis de impacto aplicables para la gestión de riesgos en proyectos de desarrollo de software. Para este estudio se realizó una revisión sistemática de la literatura en bases de datos reconocidas. Se encontraron 1654 estudios primarios de análisis de impacto aplicados a proyectos de desarrollo de software y 17 artículos definiendo 21 modelos de análisis de impacto y 1 artículo de un marco comparativo entre algunos modelos existentes. A partir del análisis realizado de los estudios primarios se puede concluir que existen modelos de análisis de impacto que se han aplicado a proyectos de desarrollo de software en distintas fases y distintos aspectos. Sin embargo, ninguno de ellos aplicado a la gestión de riesgos en proyectos de desarrollo de software.Trabajo de investigació

Identifying Behavioural Implications of Source Code Changes

The dynamic behaviour of a software system changes as a consequence of developer’s static source code modifications. In this thesis, we improve upon a previous approach that combines static and dynamic analyses to categorize behavioural changes by greatly improving its accuracy through polymorphic mapping. We further refine the previous model by introducing a change-centric state transition model that captures the flow of call pairs among different partitions based on static and dynamic call graphs. We also extend the approach by incorporating complete dynamic call stacks into the analysis. Finally, we perform a longitudinal analysis of three software systems to categorize how they have dynamically evolved across 100 program versions. In our evaluation, the polymorphic mapping algorithm decreased mismatches between the static and dynamic analyses by 53%. In particular, we decreased the mismatch by 71% in the most important category of changes from the developer’s point of view. We found that developers introduce new behaviour more often than eliminating old behaviour. Our results show that developers are more likely to remove unexecuted/dead code than code that is executed dynamically. In terms of change types, we found that changes made to fix defects encountered the least inconsistent and unexpected behaviour, while changes made to add new functionality experienced the highest unexecuted behaviour. Finally, we argue that augmenting the dynamic analyses with call stacks provides useful information that helps developers analyze the implications of the call pairs highlighted by our analyses

A review of software change impact analysis

Change impact analysis is required for constantly evolving systems to support the comprehension, implementation, and evaluation of changes. A lot of research effort has been spent on this subject over the last twenty years, and many approaches were published likewise. However, there has not been an extensive attempt made to summarize and review published approaches as a base for further research in the area. Therefore, we present the results of a comprehensive investigation of software change impact analysis, which is based on a literature review and a taxonomy for impact analysis. The contribution of this review is threefold. First, approaches proposed for impact analysis are explained regarding their motivation and methodology. They are further classified according to the criteria of the taxonomy to enable the comparison and evaluation of approaches proposed in literature. We perform an evaluation of our taxonomy regarding the coverage of its classification criteria in studied literature, which is the second contribution. Last, we address and discuss yet unsolved problems, research areas, and challenges of impact analysis, which were discovered by our review to illustrate possible directions for further research

Predicting change propagation using domain-based coupling

Most enterprise systems operate in domains where business rules and requirements frequently change. Managing the cost and impact of these changes has been a known challenge, and the software maintenance community has been tackling it for more than two decades. The traditional approach to impact analysis is by tracing dependencies in the design documents and the source code. More recently the software maintenance history has been exploited for impact analysis. The problem is that these approaches are difficult to implement for hybrid systems that consist of heterogeneous components. In today’s computer era, it is common to find systems of systems where each system was developed in a different language. In such environments, it is a challenge to estimate the change propagation between components that are developed in different languages. There is often no direct code dependency between these components, and they are maintained in different development environments by different developers. In addition, it is the domain experts and consultants who raise the most of the enhancement requests; however, using the existing change impact analysis methods, they cannot evaluate the impact and cost of the proposed changes without the support of the developers. This thesis seeks to address these problems by proposing a new approach to change impact analysis based on software domain-level information. This approach is based on the assumption that domain-level relationships are reflected in the software source code, and one can predict software dependencies and change propagation by exploiting software domain-level information. The proposed approach is independent of the software implementation, inexpensive to implement, and usable by domain experts with no requirement to access and analyse the source code. This thesis introduces domain-based coupling as a novel measure of the semantic similarity between software user interface components. The hypothesis is that the domain-based coupling between software components is correlated with the likelihood of the existence of dependencies and change propagation between these components. This hypothesis has been evaluated with two case studies: • A study of one of the largest open source enterprise systems demonstrates that architectural dependencies can be identified with an accuracy of more than 70% solely based on the domain-based coupling. • A study of 12 years’ maintenance history of the five subsystems of a significant sized proprietary enterprise system demonstrates that the co-change coupling derived from over 75,000 change records can be predicted solely using domain-based coupling, with average recall and precision of more than 60%, which is of comparable quality to other state-of-the-art change impact analysis methods. The results of these studies support our hypothesis that software dependencies and change propagation can be predicted solely from software domain-level information. Although the accuracy of such predictions are not sufficiently strong to completely replace the traditional dependency analysis methods; nevertheless, the presented results suggest that the domain-based coupling might be used as a complementary method or where analysis of dependencies in the code and documents is not a viable option

Online impact analysis via dynamic compilation technology

Dynamic impact analysis based on whole path profiling of method calls and returns has been shown to provide more useful predictions of software change impacts than methodlevel static slicing and to avoid the overhead of expensive dependency analysis needed for dynamic slicing-based impact analysis. This paper presents the design, implementation, and evaluation of an online approach to dynamic impact analysis as an extension to the DynamoRIO binary code modification system and to the Jikes Research Virtual Machine. Storage and postmortem analysis of program traces, even compressed, are avoided. 1