Armin Eberlein

Requirements engineering and agile software development

This article compares traditional requirements engineering approaches and agile software development. Our paper analyzes commonalities and differences of both approaches and determines possible ways how agile software development can benefit from requirements engineering methods.

An empirical study of open-source and closed-source software products

We describe an empirical study of open-source and closed-source software projects. The motivation for this research is to quantitatively investigate common perceptions about open-source projects, and to validate these perceptions through an empirical study. We investigate the hypothesis that open-source software grows more quickly, but does not find evidence to support this. The project growth is similar for all the projects in the analysis, indicating that other factors may limit growth. The hypothesis that creativity is more prevalent in open-source software is also examined, and evidence to support this hypothesis is found using the metric of functions added over time. The concept of open-source projects succeeding because of their simplicity is not supported by the analysis, nor is the hypothesis of open-source projects being more modular. However, the belief that defects are found and fixed more rapidly in open-source projects is supported by an analysis of the functions modified. We find support for two of the five common beliefs and conclude that, when implementing or switching to the open-source development model, practitioners should ensure that an appropriate metrics collection strategy is in place to verify the perceived benefits.

Trade-off analysis for requirements selection

Evaluation, prioritization and selection of candidate requirements are of tremendous importance and impact for subsequent software development. Eort, time as well as quality constraints have to be taken into account. Typically, dieren t stakeholders have conicting priorities and the requirements of all these stakeholders have to be balanced in an appropriate way to ensure maximum value of the nal set of requirements. Tradeo analysis is needed to proactively explore the impact of certain decisions in terms of all the criteria and constraints. The proposed method called Quantitative WinWin uses an evolutionary approach to provide support for requirements negotiations. The novelty of the presented idea is four-fold. Firstly, it iteratively uses the Analytical Hierarchy Process (AHP) for a stepwise analysis with the aim to balance the stakeholders’ preferences related to dieren t classes of requirements. Secondly, requirements selection is based on predicting and rebalancing its impact on eort, time and quality. Both prediction and rebalancing uses the simulation model prototype GENSIM. Thirdly, alternative solution sets oered for decision-making are developed incrementally based on thresholds for the degree of importance of requirements and heuristics to nd a best t to constraints. Finally, trade-o analysis is used to determine non-dominated extensions of the maximum value that is achievable under resource and quality constraints. As a main result, quantitative WinWin proposes a small number of possible sets of requirements from which the actual decision-maker can nally select the most appropriate solution.

Using different communication media in requirements negotiation

Contrary to traditional wisdom, the authors found that, when it comes to requirements negotiations, groups meeting face-to-face perform no better than those using video conferencing and computer support. Furthermore, their study identified a particular distributed group configuration that significantly improved performance and was more conducive to negotiations than face-to-face meetings.

An evaluation of scenario notations and construction approaches for telecommunication systems development

The elicitation, modeling and analysis of requirements have consistently been one of the main challenges during the development of complex systems. Telecommunication systems belong to this category of systems due to the worldwide distribution and the heterogeneity of todays telecommunication networks. Scenarios and use cases have become popular for capturing and analyzing requirements. However, little research has been done that compares different approaches and assesses their suitability for the telecommunications domain. This paper defines evaluation criteria and then reviews fifteen scenario notations. In addition, twenty-six approaches for the construction of design models from scenarios are briefly compared.

COTS Selection: Past, Present, and Future

Commercial off-the-shelf (COTS) products are increasingly being used in software development. In COTS-based development, selecting appropriate COTS is the most crucial phase. This paper explores the evolution of COTS selection practices, and surveys eighteen of the most significant COTS selection approaches. The paper traces how each approach contributed to the improvement of current COTS selection practices, and then compares them .The paper also highlights some open research issues relevant to the selection process, and concludes with a discussion of possible future directions to address these issues

An exploratory study of facilitation in distributed requirements engineering

There is an increasing need to build an understanding of group facilitation in distributed requirements engineering. Group facilitation is an important element of group approaches to requirements engineering, which is being challenged by the emergence of distributed practices in software specification and development. Thus thorough empirical investigation of human facilitation in computer-mediated requirements meetings is needed. This paper presents an exploratory study of facilitation in distributed requirements teams. Three professional facilitators mediate 15 three-person groups in an experimental simulation of software requirements negotiation. Facilitation in face-to-face meetings is contrasted with four group settings in which the facilitator is physically separated from the group or co-located with key stakeholders. Rich qualitative and behavioural data enables an understanding of differences and similarities in the facilitation of face-to-face and distributed groups and of aspects that were detrimental or beneficial to their facilitation. The empirical evidence indicates that a reduced richness of social behaviours in computer-mediated group settings (1) made the group facilitation problematic but also (2) enabled certain facilitation support in the medium itself. The findings of the study are discussed in the light of existing models of the role of the facilitator. Advice from the expert facilitators is presented in the form of recommendations for the facilitation of distributed requirements teams, and worthwhile directions for further research are outlined.

Natural language requirements analysis and class model generation using UCDA

One of the difficulties of using Artificial Neural Networks (ANNs) to estimate atmospheric temperature is the large number of potential input variables available. In this study, four different feature extraction methods were used to reduce the input vector to train four networks to estimate temperature at different atmospheric levels. The four techniques used were: genetic algorithms (GA), coefficient of determination (CoD), mutual information (MI) and simple neural analysis (SNA). The results demonstrate that of the four methods used for this data set, mutual information and simple neural analysis can generate networks that have a smaller input parameter set, while still maintaining a high degree of accuracy.

Automating transition from use-cases to class model

To identify objects from the requirements and to model the problem in classes are critical in object-oriented analysis and design (OOAD). Unfortunately, this is recognized as a hard task for most software engineers, because both domain experience and expertise are needed, since there is no crisp guideline. We present an approach with a set of artifacts and methodologies, and to automate the transition from requirement to detail design. Use cases are applied as the method to capture and record requirements. All the use cases are formalized by a use case template. A glossary that contains the domain vocabulary is used throughout the OOAD process to reduce the vagueness of natural language. Some language patterns are introduced to make the automatic processing of use cases possible. We apply robustness analysis to bridge the gap between a use case and its realization, i. e. between a use case and the corresponding collaboration diagram in UML. Some rules are summarized and adopted to automate the object/class identification and behavior distribution among the classes. The implementation of the tool is described.

Combining requirements engineering techniques - theory and case study

The selection of requirements engineering (RE) techniques during software project development is a challenge for most developers. One of the reasons is that there is a great lack of requirements engineering education in most academic programs, so software developers have to learn requirements engineering practices on the job. This can easily result in the selection of techniques that are ill-suited for a particular project, as the selection is based on personal preference rather than on the characteristics of the project. Very little research has been done in the area of technique selection based on project attributes. This paper describes research into the selection and combination of RE techniques as well as a case study that applied the selection process to an industrial software project.