978 resultados para Software Development– metrics


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Opinnäytetyö etsii korrelaatiota ohjelmistomittauksella saavutettujen tulosten ja ohjelmasta löytyneiden virheiden väliltä. Työssä käytetään koeryhmänä jo olemassaolevia ohjelmistoja. Työ tutkii olisiko ohjelmistomittareita käyttämällä ollut mahdollista paikallistaa ohjelmistojen ongelmakohdat ja näin saada arvokasta tietoa ohjelmistokehitykseen. Mittausta voitaisiin käyttää resurssien parempaan kohdentamiseen koodikatselmuksissa, koodi-integraatiossa, systeemitestauksessa ja aikataulutuksessa. Mittaamisen avulla nämä tehtävät saisivat enemmän tietoa resurssien kohdistamiseen. Koeryhmänä käytetään erilaisia ohjelmistotuotteita. Yhteistä näille kaikille tuotteille on niiden peräkkäiset julkaisut. Uutta julkaisua tehtäessä, edellistä julkaisua käytetään pohjana, jonka päällekehitetään uutta lähdekoodia. Tämän takia ohjelmistomittauksessa pitää pystyä erottelemaan edellisen julkaisun lähdekoodi uudesta lähdekoodista. Työssä käytettävät ohjelmistomittarit ovat yleisiä ja ohjelmistotekniikassalaajasti käytettyjä mittaamaan erilaisia lähdekoodin ominaisuuksia, joiden arvellaan vaikuttavan virhealttiuteen. Tämän työn tarkoitus on tutkia näiden ohjelmistomittareiden käytettävyyttä koeryhmänä toimivissa ohjelmistoympäristöissä. Käytännön osuus työstä onnistui löytämään korrelaation joidenkinohjelmistomittareiden ja virheiden väliltä, samalla kuin toiset ohjelmistomittarit eivät antaneet vakuuttavia tuloksia. Ohjelmistomittareita käyttämällä näyttää olevan mahdollista tunnistaa virhealttiit kohdat ohjelmasta ja siten parantaa ohjelmistokehityksen tehokkuutta. Ohjelmistomittareiden käyttö tuotekehityksessäon perusteltavaa ja niiden avulla mahdollisesti pystyttäisiin vaikuttamaan ohjelmiston laatuun tulevissa julkaisuissa.

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As users continually request additional functionality, software systems will continue to grow in their complexity, as well as in their susceptibility to failures. Particularly for sensitive systems requiring higher levels of reliability, faulty system modules may increase development and maintenance cost. Hence, identifying them early would support the development of reliable systems through improved scheduling and quality control. Research effort to predict software modules likely to contain faults, as a consequence, has been substantial. Although a wide range of fault prediction models have been proposed, we remain far from having reliable tools that can be widely applied to real industrial systems. For projects with known fault histories, numerous research studies show that statistical models can provide reasonable estimates at predicting faulty modules using software metrics. However, as context-specific metrics differ from project to project, the task of predicting across projects is difficult to achieve. Prediction models obtained from one project experience are ineffective in their ability to predict fault-prone modules when applied to other projects. Hence, taking full benefit of the existing work in software development community has been substantially limited. As a step towards solving this problem, in this dissertation we propose a fault prediction approach that exploits existing prediction models, adapting them to improve their ability to predict faulty system modules across different software projects.

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As users continually request additional functionality, software systems will continue to grow in their complexity, as well as in their susceptibility to failures. Particularly for sensitive systems requiring higher levels of reliability, faulty system modules may increase development and maintenance cost. Hence, identifying them early would support the development of reliable systems through improved scheduling and quality control. Research effort to predict software modules likely to contain faults, as a consequence, has been substantial. Although a wide range of fault prediction models have been proposed, we remain far from having reliable tools that can be widely applied to real industrial systems. For projects with known fault histories, numerous research studies show that statistical models can provide reasonable estimates at predicting faulty modules using software metrics. However, as context-specific metrics differ from project to project, the task of predicting across projects is difficult to achieve. Prediction models obtained from one project experience are ineffective in their ability to predict fault-prone modules when applied to other projects. Hence, taking full benefit of the existing work in software development community has been substantially limited. As a step towards solving this problem, in this dissertation we propose a fault prediction approach that exploits existing prediction models, adapting them to improve their ability to predict faulty system modules across different software projects.

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This paper presents the proposal for a reference model for developing software aimed at small companies. Despite the importance of that represent the small software companies in Latin America, the fact of not having its own standards, and able to meet their specific, has created serious difficulties in improving their process and also in quality certification. In this sense and as a contribution to better understanding of the subject they propose a reference model and as a means to validate the proposal, presents a report of its application in a small Brazilian company, committed to certification of the quality model MPS.BR.

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Dissertação apresentada para a obtenção do Grau de Doutor em Informática pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

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Tässä työssä on esitetty sen ohjelmiston kehittämisen prosessi, joka on tarkoitettu annettavien palveluiden valvottavaksi käyttäen prototyyppimallia. Raportti sisältää vaatimusten, kohteisiin suunnatun analyysin ja suunnittelun, realisointiprosessien kuvauksen ja prototyypin testauksen. Ohjelmiston käyttöala – antavien palveluiden valvonta. Vaatimukset sovellukselle analysoitiin ohjelmistomarkkinoiden perusteella sekä ohjelmiston engineeringin periaatteiden mukaisesti. Ohjelmiston prototyyppi on realisoitu käyttäen asiakas-/palvelinhybridimallia sekä ralaatiokantaa. Kehitetty ohjelmisto on tarkoitettu venäläisille tietokonekerhoille, jotka erikoistuvat pelipalvelinten antamiseen.

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Diplomityön tavoitteena oli kehittää kolmannen sukupolven fyysistä protokollakerrosta matkapuhelimen ohjelmistoarkkitehtuurille. Kolmannen sukupolven matkapuhelinjärjestelmät ovat aikaisempia järjestelmiä monimutkaisempia. Ohjelmiston koon ja monimutkaisuuden sekä aikataulujen kiireellisyyden vuoksi on tullut tarve ottaa käyttöön formaaleja menetelmiä ohjelmiston kehitystyöhön. Formaalit kuvauskielet mahdollistavat tarkan, yksiselitteisen ja simuloitavissa olevan järjestelmäkuvauksen muodostamisen. Fyysinen protokollakerros tarjoaa tiedon siirtoa ylemmille protokollakerroksille. Tämän tiedonsiirron hallinta vaatii protokollakerrosten välistä viestinvälitystä. Formaaleja kuvauskieliä käyttämällä voidaan viestinvälityksen toteutusta automatisoida ja siinä tarvittavaa logiikkaa havainnollistaa. Työssä suunniteltiin, toteutettiin ja testattiin ylempien protokollakerrosten kanssa kommunikoivaa osaa fyysisestä protokollakerroksesta. Tuloksena saatiin solunvalintatoiminnallisuuden vaatiman kommunikoinnin ja tilakoneen toteutus ohjelmistoarkkitehtuurissa. Ohjelmistonkehityksen alkuvaiheiden havaittiin olevan fyysisen kerroksen suorituskyvyn kannalta merkittävässä asemassa, koska tällöin viestinvälityksen optimointi on helpointa. Formaalit kuvauskielet eivät ole sellaisenaan täysin soveltuvia tarkoin määritellyn ohjelmistoarkkitehtuurin osien kehitykseen.

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Jatkuva laadunmittaus osana ohjelmistoprosessia on yleistynyt ohjelmistoyritysten keskuudessa viime vuosien aikana. ISO 9001:2000 -laatustandardi vaatii yrityksiltä tuotteiden ja prosessien laadun mittaamista ja seuraamista. Laadun mittareiden valinta on haastava tehtävä. Yritykset luulevat usein mittaavansa laatua, vaikka ne todellisuudessa mittaavatkin ohjelmistojen eri ominaisuuksia kuten kokoa tai monimutkaisuutta. Tässä diplomityössä kehitetään ohjelmistojen validointiprosessiin vertailuun perustuva laadunmittausprosessi ohjelmistotuotteiden laadun arviointiin, mittaamiseen ja seurantaan. Laatumittarit valitaan ennalta määriteltyjen kriteereiden mukaisesti, ja niille asetetaan tavoitearvot vertailuanalyysistä saatujen tulosten perusteella. Laadunmittausprosessin lisäksi työssä annetaan suositus prosessin käyttöönotosta ja käytöstä osana yrityksen toimintaa, mikä mahdollistaa jatkuvan seurannan sekä kehityksen tulevaisuudessa.

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Software systems are expanding and becoming increasingly present in everyday activities. The constantly evolving society demands that they deliver more functionality, are easy to use and work as expected. All these challenges increase the size and complexity of a system. People may not be aware of a presence of a software system, until it malfunctions or even fails to perform. The concept of being able to depend on the software is particularly significant when it comes to the critical systems. At this point quality of a system is regarded as an essential issue, since any deficiencies may lead to considerable money loss or life endangerment. Traditional development methods may not ensure a sufficiently high level of quality. Formal methods, on the other hand, allow us to achieve a high level of rigour and can be applied to develop a complete system or only a critical part of it. Such techniques, applied during system development starting at early design stages, increase the likelihood of obtaining a system that works as required. However, formal methods are sometimes considered difficult to utilise in traditional developments. Therefore, it is important to make them more accessible and reduce the gap between the formal and traditional development methods. This thesis explores the usability of rigorous approaches by giving an insight into formal designs with the use of graphical notation. The understandability of formal modelling is increased due to a compact representation of the development and related design decisions. The central objective of the thesis is to investigate the impact that rigorous approaches have on quality of developments. This means that it is necessary to establish certain techniques for evaluation of rigorous developments. Since we are studying various development settings and methods, specific measurement plans and a set of metrics need to be created for each setting. Our goal is to provide methods for collecting data and record evidence of the applicability of rigorous approaches. This would support the organisations in making decisions about integration of formal methods into their development processes. It is important to control the software development, especially in its initial stages. Therefore, we focus on the specification and modelling phases, as well as related artefacts, e.g. models. These have significant influence on the quality of a final system. Since application of formal methods may increase the complexity of a system, it may impact its maintainability, and thus quality. Our goal is to leverage quality of a system via metrics and measurements, as well as generic refinement patterns, which are applied to a model and a specification. We argue that they can facilitate the process of creating software systems, by e.g. controlling complexity and providing the modelling guidelines. Moreover, we find them as additional mechanisms for quality control and improvement, also for rigorous approaches. The main contribution of this thesis is to provide the metrics and measurements that help in assessing the impact of rigorous approaches on developments. We establish the techniques for the evaluation of certain aspects of quality, which are based on structural, syntactical and process related characteristics of an early-stage development artefacts, i.e. specifications and models. The presented approaches are applied to various case studies. The results of the investigation are juxtaposed with the perception of domain experts. It is our aspiration to promote measurements as an indispensable part of quality control process and a strategy towards the quality improvement.

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The goal of this thesis is to make a case study of test automation’s profitability in the development of embedded software in a real industrial setting. The cost-benefit analysis is done by considering the costs and benefits test automation causes to software development, before the software is released to customers. The potential benefits of test automation regarding software quality after customer release were not estimated. Test automation is a significant investment which often requires dedicated resources. When done accordingly, the investment in test automation can produce major cost savings by reducing the need for manual testing effort, especially if the software is developed with an agile development framework. It can reduce the cost of avoidable rework of software development, as test automation enables the detection of construction time defects in the earliest possible moment. Test automation also has many pitfalls such as test maintainability and testability of the software, and if those areas are neglected, the investment in test automation may become worthless or it may even produce negative results. The results of this thesis suggest that test automation is very profitable at the company under study.

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The vast majority of our contemporary society owns a mobile phone, which has resulted in a dramatic rise in the amount of networked computers in recent years. Security issues in the computers have followed the same trend and nearly everyone is now affected by such issues. How could the situation be improved? For software engineers, an obvious answer is to build computer software with security in mind. A problem with building software with security is how to define secure software or how to measure security. This thesis divides the problem into three research questions. First, how can we measure the security of software? Second, what types of tools are available for measuring security? And finally, what do these tools reveal about the security of software? Measuring tools of these kind are commonly called metrics. This thesis is focused on the perspective of software engineers in the software design phase. Focus on the design phase means that code level semantics or programming language specifics are not discussed in this work. Organizational policy, management issues or software development process are also out of the scope. The first two research problems were studied using a literature review while the third was studied using a case study research. The target of the case study was a Java based email server called Apache James, which had details from its changelog and security issues available and the source code was accessible. The research revealed that there is a consensus in the terminology on software security. Security verification activities are commonly divided into evaluation and assurance. The focus of this work was in assurance, which means to verify one’s own work. There are 34 metrics available for security measurements, of which five are evaluation metrics and 29 are assurance metrics. We found, however, that the general quality of these metrics was not good. Only three metrics in the design category passed the inspection criteria and could be used in the case study. The metrics claim to give quantitative information on the security of the software, but in practice they were limited to evaluating different versions of the same software. Apart from being relative, the metrics were unable to detect security issues or point out problems in the design. Furthermore, interpreting the metrics’ results was difficult. In conclusion, the general state of the software security metrics leaves a lot to be desired. The metrics studied had both theoretical and practical issues, and are not suitable for daily engineering workflows. The metrics studied provided a basis for further research, since they pointed out areas where the security metrics were necessary to improve whether verification of security from the design was desired.

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Abstract Software product metrics aim at measuring the quality of software. Modu- larity is an essential factor in software quality. In this work, metrics related to modularity and especially cohesion of the modules, are considered. The existing metrics are evaluated, and several new alternatives are proposed. The idea of cohesion of modules is that a module or a class should consist of related parts. The closely related principle of coupling says that the relationships between modules should be minimized. First, internal cohesion metrics are considered. The relations that are internal to classes are shown to be useless for quality measurement. Second, we consider external relationships for cohesion. A detailed analysis using design patterns and refactorings confirms that external cohesion is a better quality indicator than internal. Third, motivated by the successes (and problems) of external cohesion metrics, another kind of metric is proposed that represents the quality of modularity of software. This metric can be applied to refactorings related to classes, resulting in a refactoring suggestion system. To describe the metrics formally, a notation for programs is developed. Because of the recursive nature of programming languages, the properties of programs are most compactly represented using grammars and formal lan- guages. Also the tools that were used for metrics calculation are described.

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Consider the statement "this project should cost X and has risk of Y". Such statements are used daily in industry as the basis for making decisions. The work reported here is part of a study aimed at providing a rational and pragmatic basis for such statements. Of particular interest are predictions made in the requirements and early phases of projects. A preliminary model has been constructed using Bayesian Belief Networks and in support of this, a programme to collect and study data during the execution of various software development projects commenced in May 2002. The data collection programme is undertaken under the constraints of a commercial industrial regime of multiple concurrent small to medium scale software development projects. Guided by pragmatism, the work is predicated on the use of data that can be collected readily by project managers; including expert judgements, effort, elapsed times and metrics collected within each project.

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Although formal methods can dramatically increase the quality of software systems, they have not widely been adopted in software industry. Many software companies have the perception that formal methods are not cost-effective cause they are plenty of mathematical symbols that are difficult for non-experts to assimilate. The Java Modelling Language (short for JML) Section 3.3 is an academic initiative towards the development of a common formal specification language for Java programs, and the implementation of tools to check program correctness. This master thesis work shows how JML based formal methods can be used to formally develop a privacy sensitive Java application. This is a smart card application for managing medical appointments. The application is named HealthCard. We follow the software development strategy introduced by João Pestana, presented in Section 3.4. Our work influenced the development of this strategy by providing hands-on insight on challenges related to development of a privacy sensitive application in Java. Pestana’s strategy is based on a three-step evolution strategy of software specifications, from informal ones, through semiformal ones, to JML formal specifications. We further prove that this strategy can be automated by implementing a tool that generates JML formal specifications from a welldefined subset of informal software specifications. Hence, our work proves that JML-based formal methods techniques are cost-effective, and that they can be made popular in software industry. Although formal methods are not popular in many software development companies, we endeavour to integrate formal methods to general software practices. We hope our work can contribute to a better acceptance of mathematical based formalisms and tools used by software engineers. The structure of this document is as follows. In Section 2, we describe the preliminaries of this thesis work. We make an introduction to the application for managing medical applications we have implemented. We also describe the technologies used in the development of the application. This section further illustrates the Java Card Remote Method Invocation communication model used in the medical application for the client and server applications. Section 3 introduces software correctness, including the design by contract and the concept of contract in JML. Section 4 presents the design structure of the application. Section 5 shows the implementation of the HealthCard. Section 6 describes how the HealthCard is verified and validated using JML formal methods tools. Section 7 includes some metrics of the HealthCard implementation and specification. Section 8 presents a short example of how a client-side of a smart card application can be implemented while respecting formal specifications. Section 9 describes a prototype tools to generate JML formal specifications from informal specifications automatically. Section 10 describes some challenges and main ideas came acrorss during the development of the HealthCard. The full formal specification and implementation of the HealthCard smart card application presented in this document can be reached at https://sourceforge.net/projects/healthcard/.

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Software Product Line (SPL) consists of a software development paradigm, whose main focus is to identify features common and variability among applications in a specific domain. An LPS is designed to attend all products requirements from its product family. These requirements and LPS may have changes over time due to several factors, such as evolution of product requirements, evolution of the market, evolution of SLP process, evolution of the technologies used to develop the products. To handle these changes, LPS should be modified and evolve in order to not become obsolete, and adapt itself to new requirements. The Changes Impact Analysis is an activity that understand and identify what consequences these changes are cause on LPS. Impact Analysis on LPS may be supported by traceability relationships, which identify relationships between artefacts created during all phases of software development. Despite the solutions of change impact analysis based on traceability for software, there is a lack of solutions for assessing the change impact analysis based on traceability for LPS, since existing solutions do not include estimates specific to the artefacts of LPS. Thus, this paper proposes a process of change impact analysis and an tool for assessing the change impact through traceability of artefacts in LPS. For this purpose, we specified a process of change impact analysis that considers artifacts produced during the development of LPS. We have also implemented a tool which allows estimating and identifying artefacts and products of LPS affected from changes in other products, changes in class, changes in features, changes between releases of LPS and artefacts related to changes in core assets and variability. Finally, the results were evaluated through metrics