The cloning of code is controversial as a development practice. Empirical studies on the long-term effects of cloning on software quality and maintainability have produced mixed results. Some studies have found that cloning has a negative impact on code readability, bug propagation, and the presence of cloning may indicate wider problems in software design and management. At the same time, other studies have found that cloned code is less likely to have defects, and thus is arguably more stable, better designed, and better maintained. These results suggest that the effect of cloning on software quality and maintainability may be determinable only on a case-by-case basis, and this only aggravates the challenge of establishing a principled framework of clone management and understanding. This thesis aims to improve the understanding and management of clones within software systems. There are two main contributions. First, we have conducted an empirical study on cloning in one of the major device drivers families of the Linux kernel. Different from many previous empirical studies on cloning, we incorporate the knowledge about the development style, and the architecture of the subject system into our study; our findings address the evolution of clones; we have also found that the presence of cloning is a strong predictor (87\% accuracy) of one aspect of underlying hardware similarity when compared to a vendor-based model (55\% accuracy) and a randomly chosen model (9\% accuracy). The effectiveness of using the presence of cloning to infer high-level similarity suggests a new perspective of using cloning information to assist program comprehension, aspect mining, and software product-line engineering. Second, we have devised a triage-oriented taxonomy of clones to aid developers in prioritizing which kinds of clones are most likely to be problematic and require attention; a preliminary validation of the utility of this taxonomy has been performed against a large open source system. The cloning-based software quality assurance (QA) framework based on our taxonomy adds a new dimension to traditional software QA processes; by exploiting the clone detection results within a guided framework, the developer is able to evaluate which instances of cloning are most likely to require urgent attention.

The cloning of code is controversial as a development practice. Empirical studies on the long-term effects of cloning on software quality and maintainability have produced mixed results. Some studies have found that cloning has a negative impact on code readability, bug propagation, and the presence of cloning may indicate wider problems in software design and management. At the same time, other studies have found that cloned code is less likely to have defects, and thus is arguably more stable, better designed, and better maintained. These results suggest that the effect of cloning on software quality and maintainability may be determinable only on a case-by-case basis, and this only aggravates the challenge of establishing a principled framework of clone management and understanding. This thesis aims to improve the understanding and management of clones within software systems. There are two main contributions. First, we have conducted an empirical study on cloning in one of the major device drivers families of the Linux kernel. Different from many previous empirical studies on cloning, we incorporate the knowledge about the development style, and the architecture of the subject system into our study; our findings address the evolution of clones; we have also found that the presence of cloning is a strong predictor (87\% accuracy) of one aspect of underlying hardware similarity when compared to a vendor-based model (55\% accuracy) and a randomly chosen model (9\% accuracy). The effectiveness of using the presence of cloning to infer high-level similarity suggests a new perspective of using cloning information to assist program comprehension, aspect mining, and software product-line engineering. Second, we have devised a triage-oriented taxonomy of clones to aid developers in prioritizing which kinds of clones are most likely to be problematic and require attention; a preliminary validation of the utility of this taxonomy has been performed against a large open source system. The cloning-based software quality assurance (QA) framework based on our taxonomy adds a new dimension to traditional software QA processes; by exploiting the clone detection results within a guided framework, the developer is able to evaluate which instances of cloning are most likely to require urgent attention.

Context. Global software development (GSD) gained huge recognition in today’s business world. Most of the software companies day by day are striving hard to evolve globally where software is developed in the context of different environmental settings that are distanced on various factors like geography, timezone, culture and language. Coordination is the factor that plays one of the prominent roles in such a setting for effective teamwork and project success. Although numerous efforts has been done in this research area, there has been no proper evidence from industry about the impact of these coordination challenges on the overall quality of the software when being developed in a distributed setting. Objectives. The purpose of this study is to examine and identify the coordination challenges and risks faced in global software development projects that has a negative impact on the quality of software from practitioner’s perspective. It also identify the tools, methods, and techniques that are used in industry to overcome these challenges and maintain quality standards. Methods. The aims and objectives of our study are fulfilled by conducting survey among practitioners working in GSD projects all around the globe. Further, 10 interviews are conducted with practitioners working in different companies and geographical locations in order to gain a detailed understanding of the impact of identified coordination challenges on the quality of software in GSD projects. Results. A total of 50 survey responses are recorded, out of which 48 respondents specify that coordination challenges has a negative impact on software quality in GSD context. By the ratings given by the participants, we identified the challenges and risks that had a major impact. Mixed results are obtained during interviews where most of them prioritized coordination as a major problem in GSD projects. It also included that use of some tools, methods and processes help them in overcoming this issue. The quality attributes that are mostly affected due to the challenges in GSD projects are also identified. Conclusions. After the analysis of survey results, the coordination challenges and associated risks in GSD projects are identified. They were found to havemostly negative impact on software quality. After thematic analysis of interview results, we observed that though the impact of coordination challenges is negative, its extent of implication is moderate in most cases.

Requirements Engineering and Software Quality Management is nowadays considered to be one of the important parts of the software development process. This thesis deals with connecting the theoretical concept of requirements engineering and usage of functions offered by Enterprise Architect tool, which should support the requirements engineering and software quality management processes. The main goal is to propose procedures of Enterprise Architect usage during the project in such a way, which will help to raise quality of the final product. The purpose is to offer a systematic and conscious way of implementation Enterprise Architect elements into software development processes, because this tool is able to support the whole cycle of the product. The methodology was designed as a result of theoretical concept, existing requirements engineering approaches and my own experience acquired during working on projects as a business and test analyst. The contribution of the designed methodology is in bringing recommendations, practices and procedures saying how to use Enterprise Architect during the software development process in order to gain the highest possible software quality. The thesis is structured in four sections describing the appropriate theory, analyzed requirement engineering approaches, critical mistakes during this process and the methodology design.

The goal of this thesis is to create a proposal of framework which can be used to support software quality management in a small development company. Framework is composed of processes, methodologies and tools which together should improve the quality of software products of a company. Concrete implementation of the framework is shown as a case study. Data for the case study were collected in the company Cleverbee, where the author worked during the case study's creation. Personal contribution of the author of the thesis is firstly the creation of the framework concept based on author's experiences and commented list of concrete results of framework's implementation. The detailed goal setting for this thesis and the definition of the target reader can be found in the chapter 1. Introduction. The definition of main terms, which will appear in the rest of the thesis, is contained in the chapter 2. Terms. Chapter 3. Software quality and its definition is explains the term "software quality" and the nature of the small companies. Chapter 4. Software quality management forms the theoretical foundation of the thesis. In this chapter you find how the methodologies RUP and CMMI view the software quality. Chapter 5. Framework concept contains the concept of the software quality management framework. Framework is based upon relevant sources and also author's personal experience. The chapter 6. Case study describes the concrete example of the implementation of the proposed framework. The case study also contains descriptions of the used software tools. The chapter 7. Conclusion contains the brief resume of the findings of the thesis.