published_or_final_version / abstract / Computer Science / Master / Master of Philosophy

published_or_final_version / abstract / Computer Science / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

Any guidance that might help to reduce the problems of accurately estimating software development effort could assist software producers to set more realistic budgets for software projects. This investigation attempted to make a contribution to this by documenting some of the practical problems with introducing structured effort estimation models at a site in the United Kingdom of an international supplier of telephone switching software. The theory of effort modelling was compared with actual practice by examining how the estimating experts at the telephone switching software producer currently carried out estimating. Two elements of the estimation problem emerged: judging the size of the job to be done and gauging the productivity of the development environment. Expert opinion was particularly important to the initial process, particularly when existing software was being enhanced. The study then identified development effort drivers and customised effort models applicable to real-time telecommunications applications. Many practical difficulties were found concerning the actual methods used to record past project data, although the issues surrounding these protocols appeared to be rarely dealt with explicitly in the research literature. The effectiveness of the models was trialled by forecasting the effort for some new projects and then comparing these estimates with the actual effort. The key research outcomes were, firstly the identification and validation of a set of relevant functional effort drivers applicable in a real-time telecommunications software development environment and the building of an effective effort model, and, secondly, the evaluation of alternative prediction approaches including analogy or case-based reasoning. While analogy was a useful tool, some methods of implementing analogy were flawed theoretically and did not consistently outperform 'traditional' model building techniques such as Least Squares Regression (LSR) in the environment under study. This study would, however, support analogy as a complementary technique to algorithmic modelling

In the first part of this study software metrics are classified into three categories: primitive, abstract and structured. A comparative and analytical study of metrics from these categories was performed to provide software developers, users and management with a correct and consistent evaluation of a representative sample of the software metrics available in the literature. This analysis and comparison was performed in an attempt to: assist the software developers, users and management in selecting suitable quality metric(s) for their specific software quality requirements and to examine various definitions used to calculate these metrics. In the second part of this study an approach towards attaining software quality is developed. This approach is intended to help all the people concerned with the evaluation of software quality in the earlier stages of software systems development. The approach developed is intended to be uniform, consistent, unambiguous and comprehensive and one which makes the concept of software quality more meaningful and visible. It will help the developers both to understand the concepts of software quality and to apply and control it according to the expectations of users, management, customers etc.. The clear definitions provided for the software quality terms should help to prevent misinterpretation, and the definitions will also serve as a touchstone against which new ideas can be tested.

This thesis examines alternative prototyping processes as a means of implementing manufacturing information systems in a small to medium sized batch process manufacturing company. Prototyped IS (Information Systems) ate compared to other systems designed and implemented according to the traditional Systems Development Life Cycle model. Action research is used in conjunction with an IS case study framework. as the strategy to provide a rich analysis of the power, political, organizational and business effects resulting from the prototype implementations. Survey and structured interview methods are used to assess the rate of spread and extent of prototyped versus non prototyped IS applications. Perceptions of IS user managers from both prototyped and non prototyped systems are measured using an IS user satisfaction measurement tool. Alternative manufacturing information systems implementation methodological choices are examined resulting in the identification of three paradigms important to the appropriate selection of implementation methodology dependent on manufacturing environment context: Systems ProblemlLearninglAction (SPLA); Systems Engineering; and Systems Architecture. Prototyping is identified as belonging to the SPLA paradigm characterized by 'soft' systems methodologies orientated to problem solving by an iterative process of learning. Conclusions from this multi-disciplinary research enquiry are that prototyping is a viable implementation methodology with defInite performance improvements over traditional methodologies. A five dimensional framework for prototyping manufacturing information systems is proposed. The five dimensions: IS Strategy; Organizational; User; Business; and Prototyping provide a mechanism (or planning and managing the prototyping process. Recommendations are made for more research to be carried out into the derivation of a structure for the evolutionary prototyping process, for more investigation into the problems of early implementation of prototypes, whilst maintaining technical and quality integrity, and for more field studies to identify potential implementation contexts of the prototypingframework.

Software testing is the most widely practiced approach to assure the correctness of programs. Despite decades of research progress, software testing is still considered very resource-demanding and time-consuming. In the recent decade, the wide adoption of multithreaded programs and the service-based architecture has further aggravated the problem that we are facing. In this thesis, we study issues in software testing where resource constraints (such as time spent and memory space allocated) are important considerations, and we look for testing techniques that are significantly advanced in effectiveness and efficiency given limited quotas of resources, which we refer to as budget. Our main focus is on two types of systems: concurrent systems and service-based systems. The concurrent system is a class of computing system where programs are designed as collections of interacting and parallel computational processes. Unfortunately, concurrent programs are well known to be difficult to write and test: various concurrency bugs still exist in heavily-tested programs. To make it worse, detecting concurrency bugs is expensive, which is, for example, notorious for dynamic detection techniques that target high precision. This thesis proposes a dynamic sampling framework, CARISMA, to reduce the overhead dramatically while still largely preserving the bug detection capability. To achieve its goal, CARISMA intelligently allocates the limited budget on the computation resource through sampling. The core of CARISMA is a budget estimation and allocation framework whose correctness has been proven mathematically. Another source of cost comes from the nondeterministic nature of concurrent systems. A common practice to test concurrent system is through stress testing where a system is executed with a large number of test cases to achieve a high coverage of the execution space. Stress testing is inherently costly. To this end, it is critical that the bug detection for each execution is effective, which demands a powerful test oracle. This thesis proposes such a test oracle, OLIN, which reports anomalies in the concurrent executions of programs. OLIN finds concurrency bugs that are consistently missed by previous techniques and incurs low overhead. OLIN can achieve a higher effectiveness within given time and computational budgets. Service-based systems are composed of loosely coupled and unassociated units of functional units and are often highly concurrent and distributed. We have witnessed their prosperity in recent decades. Service-based systems are highly dynamic and regression testing techniques are applied to ensure their previously established functionality and correctness are not adversely affected by subsequent evolutions. However, regression testing is expensive and our thesis focuses on the prioritization of regression test cases to improve the effectiveness of testing within predefined constraints. This thesis proposes a family of prioritization metrics for regression testing of location-based services and presents a case study to evaluate their performance. In conclusion, this thesis makes the following contributions to software testing and analysis: (1) a dynamic sampling framework for concurrency bug detection, (2) a test oracle for concurrent testing, and (3) a family of test case prioritization techniques for service-based systems. These contributions significantly improve the effectiveness and efficiency of resource utilization in software testing. / published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

(kein Abstract vorhanden) / Series: Schriftenreihe des Instituts für Transportwirtschaft und Logistik - Supply Chain Management

<p>The current mobile technology is growing very fast, and it has already included many excellent features on mobile phones. Current mobile technology research mainly aims at fast execution and enriching mobile phone with more and more portable features.</p><p>This thesis aims at a thorough investigation of <strong>Android </strong>enabled mobile phone’s capabilities. Mobile devices today may utilize several types of sensors. These sensors may be used to sense the environment, in which, the device is situated, directly or indirectly. The main idea is to connect sensing with end‐user programming (EUP). We enumerate some challenges that will be addressed in this thesis. This thesis is exploratory, which implies that it contains a survey of available techniques, tools, and approaches particularly in the mobile device domain. In addition the thesis will also explore and identify the limits with focus on the Android platform.</p><p>Thesis Implementation languages are mainly Core Java, Android 2.1 programming language and XML. We have developed Sensors framework using Android API, which gives latest value of all possible sensors used in mobile phones, and notify end user programming about sensor value change. We have also developed ECA (Event Condition Action) framework, for end user programming to handle end user configuration changes.</p><p>The thesis research and implementation results helped us to find answers for various challenges on mobile phone domain. Few of them to mention are, gathering information about different kinds of sensors, how they can be used for sensing real time environment, how we can combine different sensing results to identify particular action, identifying framework and domain language for end user programming.</p>

<p>Paramount Salt Handicraft A wholesale Himalayan salt company was previously doing business in traditional way and was limited only to the local market. However from the start day management was planning to expand the business to more locations and to attract more customers. So to expand the business and to attract the international customers and customers from other cities of Sweden it was necessary to make it available over the internet so that customers can easily get knowledge about the company’s products and purchase them. So the need of an online web shop was realized to bring the company’s plan into reality. The online shop will be act as a medium of interaction between the customers and the company and it will enable the customers to buy products online and make payments electronically and after that the products will delivered to them. Throughout the process the customers can easily track the overall status of their orders.</p>