Comparative Study on Agile software development methodologies

Today-s business environment is very much dynamic, and organisations are constantly changing their software requirements to adjust with new environment. They also demand for fast delivery of software products as well as for accepting changing requirements. In this aspect, traditional plan-driven developments fail to meet up these requirements. Though traditional software development methodologies, such as life cycle-based structured and object oriented approaches, continue to dominate the systems development few decades and much research has done in traditional methodologies, Agile software development brings its own set of novel challenges that must be addressed to satisfy the customer through early and continuous delivery of the valuable software. It is a set of software development methods based on iterative and incremental development process, where requirements and development evolve through collaboration between self-organizing, cross-functional teams that allows rapid delivery of high quality software to meet customer needs and also accommodate changes in the requirements. In this paper, we significantly identify and describe the major factors, that Agile development approach improves software development process to meet the rapid changing business environments. We also provide a brief comparison of agile development methodologies with traditional systems development methodologies, and discuss current state of adopting agile methodologies. We speculate that from the need to satisfy the customer through early and continuous delivery of the valuable software, Agile software development is emerged as an alternative to traditional plan-based software development methods. The purpose of this paper, is to provide an in-depth understanding, the major benefits of agile development approach to software development industry, as well as provide a comparison study report of ASDM over TSDM.Comment: 25 pages, 25 images, 86 references used, with authors biographie

Estimating Agile Software Project Effort: An Empirical Study

This paper describes an empirical study of effort estimation in agile software development. Estimated effort and actual effort of a 46-iteration project are collected and analyzed. The results show that estimation in agile development is more accurate than that in traditional development even though agile developers still underestimate the effort. However, estimation accuracy is not improved over time as expected by agile communities

The Empirical Reality of IT Project Cost Overruns: Discovering A Power-Law Distribution

If managers assume a normal or near-normal distribution of Information Technology (IT) project cost overruns, as is common, and cost overruns can be shown to follow a power-law distribution, managers may be unwittingly exposing their organizations to extreme risk by severely underestimating the probability of large cost overruns. In this research, we collect and analyze a large sample comprised of 5,392 IT projects to empirically examine the probability distribution of IT project cost overruns. Further, we propose and examine a mechanism that can explain such a distribution. Our results reveal that IT projects are far riskier in terms of cost than normally assumed by decision makers and scholars. Specifically, we found that IT project cost overruns follow a power-law distribution in which there are a large number of projects with relatively small overruns and a fat tail that includes a smaller number of projects with extreme overruns. A possible generative mechanism for the identified power-law distribution is found in interdependencies among technological components in IT systems. We propose and demonstrate, through computer simulation, that a problem in a single technological component can lead to chain reactions in which other interdependent components are affected, causing substantial overruns. What the power law tells us is that extreme IT project cost overruns will occur and that the prevalence of these will be grossly underestimated if managers assume that overruns follow a normal or near-normal distribution. This underscores the importance of realistically assessing and mitigating the cost risk of new IT projects up front

A Systematic Mapping of Factors Affecting Accuracy of Software Development Effort Estimation

Software projects often do not meet their scheduling and budgeting targets. Inaccurate estimates are often responsible for this mismatch. This study investigates extant research on factors that affect accuracy of software development effort estimation. The purpose is to synthesize existing knowledge, propose directions for future research, and improve estimation accuracy in practice. A systematic mapping study (a comprehensive review of existing research) is conducted to identify such factors and their impact on estimation accuracy. Thirty-two factors assigned to four categories (estimation process, estimator’s characteristics, project to be estimated, and external context) are identified in a variety of research studies. Although the significant impact of several factors has been shown, results are limited by the lack of insight into the extent of these impacts. Our results imply a shift in research focus and design to gather more in-depth insights. Moreover, our results emphasize the need to argue for specific design decisions to enable a better understanding of possible influences of the study design on the credibility of the results. For software developers, our results provide a useful map to check the assumptions that undergird their estimates, to build comprehensive experience databases, and to adequately staff design projects

A Study of Software Development Models for Small Organisations

Software Development is a complex and often difficult process requiring the synthesis of many disciplines, like modelling and design to code generation, project management, testing, deployment, change management and beyond. Software development organizations follow some process while developing a software product. A key component of any software development process is the lifecycle model on which the process is based

Empirical research on Software Effort Estimation Accuracy

To improve the software development process is named by both the European Union and the United States government as an important task for society. The constant problem with effort overruns and estimation inaccuracy is a main part of the software development problem. Empirical research on software effort estimation is a key part of the continuing effort by researchers and practitioners to improve the way in which software development projects are carried out. As part of this effort, a study on eighteen of the latest projects at a Norwegian software consultancy was done. The study was done by interviewing the project managers responsible for the projects, having them provide key project data, and their assessments of different project properties related to effort estimation. The study focused on answering research questions related to: • The effect the contractor-customer relationship and customer properties have on estimation accuracy • The effect utilizing experience data has on estimation accuracy • The role of estimation accuracy when assessing software project success The analysis of the collected empirical data showed that reduced effort overruns was associated with increased contact frequency with the customer and contracts that share the risk between contractor and customer. Utilization of experience data, and the use of checklists, was also found to have a positive impact on estimation accuracy. There was not found any strong correlation between project managers’ project success assessment and estimation accuracy, indicating that estimation accuracy and project manager success assessment contribute with two different, but important viewpoints when software project success is to be assessed. In addition to the empirical study and its results, the thesis presents a review of existing group combination techniques for software effort estimation. The review was motivated by recent studies that have suggested that to do software estimation as a group is beneficial. The review presents techniques that vary largely as to how they structure the interaction among the group members, and how their opinions are aggregated. A thorough discussion on the argumentation behind the techniques, and the consequences they have is given in the review. The empirical data collected during the work with this thesis suggests different ways in which software contractors could improve their estimation ability and reduce their effort overruns. The conclusions of this thesis is, that to increase estimation accuracy, software contractors should: (i) involve the customer, and nurture the customer relationship, (ii) add some repeatable structure to the estimation process, but be careful not to add too much structure, (iii) gather and utilize experience data in the estimation process and (iv) evaluate projects when they are done. In doing the evaluation both objective data on effort, schedule and functionality compliance and subjective assessments of project success from key stakeholders, as customer, user, project manager, developers and management should be gathered

A Software Development Simulation Model of a Spiral Process

There is a need for simulation models of software development processes other than the waterfall because processes such as spiral development are becoming more and more popular. The use of a spiral process can make the inherently difficult job of cost and schedule estimation even more challenging due to its evolutionary nature, but this allows for a more flexible process that can better meet customers' needs. This paper will present a discrete event simulation model of spiral development that can be used to analyze cost and schedule effects of using such a process in comparison to a waterfall process