Summary Predictive mutation testing (PMT) is a technique to predict whether a mutant is killed, using machine learning approaches. Researchers have proposed various methods for PMT over the years. However, the impact of unreached mutants on PMT is not fully addressed. A mutant is unreached if the statement on which the mutant is generated is not executed by any test cases. We aim at showing that unreached mutants can inflate PMT results. Moreover, we propose an alternative approach to PMT, suggesting a different interpretation for PMT. To this end, we replicated the previous PMT research. We empirically evaluated the suggested approach on 654 Java projects provided by prior literature. Our results indicate that the performance of PMT drastically decreases in terms of area under a receiver operating characteristic curve (AUC) from 0.833 to 0.517. Furthermore, PMT performs worse than random guesses on 27% of the projects. The proposed approach improves the PMT results, achieving the average AUC value of 0.613. As a result, we recommend researchers to remove unreached mutants when reporting the results.

In software testing, different metrics are proposed to predict and compare test suites effectiveness. In this regard, Mutation Score (MS) is one of most accurate metrics. However, calculating MS needs executing test suites many times and it is not commonly used in industry. On the other hand, Line Coverage (LC) is a widely used metric which is calculated by executing test suites only once, although it is not as accurate as MS in terms of predicting and comparing test suites effectiveness. In this paper, we propose a novel test coverage metric, called Program State Coverage (PSC), which improves the accuracy of LC. PSC works almost the same as LC and it can be calculated by executing test suites only once. However, it further considers the number of distinct program states in which each line is executed. Our experiments on 120 test suites from four packages of Apache Commons Math and Apache Commons Lang show that, compared to LC, PSC is more strongly correlated with normalized MS. As a result, we conclude that PSC is a promising test coverage metric.

Abstract The increase in complexity and rate of technological changes in modern software development has led to a demand for systematic methods that raise the abstraction level for system maintenance and regression testing. Model‐driven development (MDD) has promised to reduce extra coding efforts in software maintenance activities using traceable change management. The research described in this paper presents a Z‐notation‐based framework, called delta‐based regression testing (DbRT), for formal modeling of regression testing in the context of MDD. The framework proposes to propagate the changes from a software specification to testing artifacts in order to preserve consistency after system evolution. Also, an effective delta‐based selection technique is provided for regression testing at the platform‐independent level. The framework is further enriched by introducing a new category of coverage patterns for DbRT. Complex coverage patterns can be defined using a declarative query language syntax for examining the adequacy of regression testing. Finally, an implementation technique and an analysis plan are provided to assess the effectiveness of the proposed framework. The assessment process is expected to be beneficial to both the platform‐independent and platform‐specific level of DbRT by identifying the desired coverage according to available testing resources. Copyright © 2015 John Wiley & Sons, Ltd.

In our previous work, we presented a Z-based formalism, called NZ, by which one can explicitly specify bounded, unbounded, erratic, angelic, demonic, loose, strict, singular, and plural nondeterminism. The NZ notation is mainly based on a new notion of operation schemas, called multi-schema. Since the operations of the Z schema calculus do not work on multi-schemas anymore, in this paper we augment NZ with a new set of schema calculus operations that can be applied on multi-schemas as well as ordinary operation schemas. To demonstrate the usability of the resulting formalism, we show how this formalism can assist to model game-like situations and concurrent systems as two well-known classes of nondeterministic systems.

Test Driven Development (TDD), as a quality promotion approach, suffers from some shortages that discourage its usage. One of the most challenging shortcomings of TDD is the low level of granularity and abstraction. This may lead to production of software that is not acceptable by the end users. Additionally, exploiting of TDD is not applicable in the enterprise systems development. To overcome this defect, we have merged TDD with Model Based Testing (MBT) and suggested a framework named Model Based Test Driven Development (MBTDD). According to TDD, writing test cases comes before programming, and based on our improved method of TDD, modeling precedes writing test cases. To validate the applicability of the proposed framework, we have implemented a use case of Human Resource Management (HRM) system by means of MBTDD. The empirical results of using MBTTD show that our proposed method overwhelms existing deficiencies of TDD.

Dealing with crosscutting requirements in software development usually makes the process more complex. Modeling and analyzing of these requirements in the software architecture facilitate detecting architectural risks early. Distributed systems have more complexity and so these facilities are much useful in development of such systems. Aspect oriented Architectural Description Languages (ADD) have emerged to represent solutions for discussed problems; nevertheless, imposing radical changes to existing architectural modeling methods is not easily acceptable by architects. Software architecture analysis methods, furthermore, intend to verify that the quality requirements have been addressed properly. In this paper, we enhance ArchC# through utilization of aspect features with an especial focus on Non-Functional Requirements (NFR). ArchC# is mainly focused on describing architecture of distributed systems; in addition, it unifies software architecture with an object- oriented implementation to make executable architectures. Moreover, in this paper, a comparative analysis method is presented for evaluation of the result. All of these materials are illustrated along with a case study.

Because of several vulnerabilities in software products and high amount of damage caused by them, software developers are enforced to produce more secure systems. Software grows up through its life cycle, so software development methodologies should pay special attention to security aspects of the product. This paper focuses on agile methodologies in order to equip them with security activities. We can restrain reduction of agile nature of organization's current process by means of agility measurement and applying an efficient activity integration algorithm with a tunable parameter named agility reduction tolerance (ART). Using this approach, method engineer of the project can enhance his agile software development process with security features to increase product's trustworthiness.

An approach to Z-style program specification is developed based upon a constructive version of Zermelo-Fraenkel set theory without replacement. The idea of obligation schema, an extension of Z-schema, is introduced, and an implementation of this notion presented which facilitates the abstraction of programs.