Mohamad Kassab

An Ontology Based Approach to Non-functional Requirements Conceptualization

The growing awareness of the importance of Non- Functional Requirements (NFRs) among the requirements engineering (RE) community in the last few years led to a heightened interest in NFRs description and modeling and, in turn, to the emergence of several models intended to capture and structure the relevant concepts defining the NFRs and their relations. Yet, most of the terms and concepts in use for describing NFRs have been loosely defined, and often there is no commonly accepted taxonomy of NFRs. Common Foundation is required to enable effective communication and to enable integration of NFRs’ related research activities within the RE community. In this paper, this Common Foundation will be realized by developing an ontology-based approach which is adequate for projects taking into consideration the NFRs and their relations earlier in the software development and throughout the life cycle.

State of practice in requirements engineering: contemporary data

Little contemporary data exists that documents software requirements elicitation, requirements specification, document development, and specification validation practices. An exploratory survey of more than 3,000 software professionals was conducted and nearly 250 responses were obtained. Survey data obtained includes characteristics of projects, practices, organizations, and practitioners related to requirements engineering. Selected results are presented along with interpretations of this data.

The changing landscape of requirements engineering practices over the past decade

Even though there is ample information available on solid requirements engineering practices, anecdotal evidence still indicates poor practices in industry. The key issue in implementing an improvement is to first identify the areas that need most improvement. Three surveys were conducted in 2003, 2008 and 2013 on the state of practice of requirements engineering. Surveys data obtained includes characteristics of projects, practices, organizations, and practitioners related to requirements engineering. In this paper we present a comparison and analysis of the responses from the three surveys in order to understand the changing land-scape of requirements engineering industrial practices over the past years.

Would you mind fixing this issue

A successful software project is the result of a complex process involving, above all, people. Developers are the key factors for the success of a software development process and the Agile philosophy is developer-centred. Developers are not merely executors of tasks, but actually the protagonists and core of the whole development process. This paper aims to investigate social aspects among developers working together and the appeal of a software project developed with the support of Agile tools such as Agile boards. We studied 14 open source software projects developed using the Agile board of the JIRA repository. We analysed all the comments committed by the developers involved in the projects and we studied whether the politeness of the comments affected the number of developers involved over the years and the time required to fix any given issue. Our results show that the level of politeness in the communication process among developers does have an effect on the time required to fix issues and, in the majority of the analysed projects, it has a positive correlation with attractiveness of the project to both active and potential developers. The more polite developers were, the less time it took to fix an issue, and, in the majority of the analysed cases, the more the developers wanted to be part of project, the more they were willing to continue working on the project over time.

Non-Functional Requirements Size Measurement Method (NFSM) with COSMIC-FFP

Non-functional requirements (NFRs) of software systems are an important source of uncertainty in effort estimation. Furthermore, quantitatively approaching NFR early in a project is difficult. This paper makes a step towards reducing the impact of uncertainty due to NFRs. It offers a new generic classification of the NFRs, and a NFR size measurement method (NFSM) that incorporates NFRs into the functional size quantification process. We chose the NFR framework as a vehicle to integrate NFRs into the requirements modeling process and to apply quantitative assessment procedures. Our solution proposal also rests on the functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard. We discuss the advantages of our approach and the open questions related to its design as well.

A Quantitative Evaluation of the Impact of Architectural Patterns on Quality Requirements

When designing software architectures, an architect relies on a set of pre-defined styles commonly named architectural patterns. While architectural patterns embody high level design decisions, an architectural tactic is a design strategy that addresses a particular quality attribute. Tactics; in fact, serve as the meeting point between the quality attributes and the software architecture. To guide the architect in selecting the most appropriate architectural patterns and tactics, the interactions between quality attributes, tactics and patterns should be analyzed and quantified and the results should be considered as decision criteria within a quality-driven architectural design process. In this paper, we propose an approach for a quantitative evaluation of the support provided by a pattern for a given targeted set of quality attributes.

An integrated approach of AHP and NFRs framework

One of the challenging areas in dealing with Non-Functional Requirements (NFRs) is the need for a decision support system which helps in a better trade-off among alternative operationalizations in the potential solution space for the NFRs. Dealing with such a trade-off is popularly treated with a qualitative fashion through the NFRs framework. In this paper, we propose the incorporation of the mathematical based trade-off technique: Analytical Hierarchy Process (AHP) to quantitatively deal with ambiguities, trade-offs, priorities and interdependencies among NFRs and operationalizations when using the NFRs framework. Such usage of the AHP technique within the NFRs framework will bring the benefits of the mathematically based trade-off techniques to the NFRs framework and eliminates the drawbacks associated with model-based trade-off techniques which the NFRs framework belongs to.

Quantifying the Impact of Different Non-functional Requirements and Problem Domains on Software Effort Estimation

The effort estimation techniques used in the software industry often tend to ignore the impact of Non-functional Requirements (NFR) on effort and reuse standard effort estimation models without local calibration. Moreover, the effort estimation models are calibrated using data of previous projects that may belong to problem domains different from the project which is being estimated. Our approach suggests a novel effort estimation methodology that can be used in the early stages of software development projects. Our proposed methodology initially clusters the historical data from the previous projects into different problem domains and generates domain specific effort estimation models, each incorporating the impact of NFR on effort by sets of objectively measured nominal features. We reduce the complexity of these models using a feature subset selection algorithm. In this paper, we discuss our approach in details, and we present the results of our experiments using different supervised machine learning algorithms. The results show that our approach performs well by increasing the correlation coefficient and decreasing the error rate of the generated effort estimation models and achieving more accurate effort estimates for the new projects.

Managing requirement volatility in an ontology-driven clinical LIMS using category theory

Requirement volatility is an issue in software engineering in general, and in Web-based clinical applications in particular, which often originates from an incomplete knowledge of the domain of interest. With advances in the health science, many features and functionalities need to be added to, or removed from, existing software applications in the biomedical domain. At the same time, the increasing complexity of biomedical systems makes them more difficult to understand, and consequently it is more difficult to define their requirements, which contributes considerably to their volatility. In this paper, we present a novel agent-based approach for analyzing and managing volatile and dynamic requirements in an ontology-driven laboratory information management system (LIMS) designed for Web-based case reporting in medical mycology. The proposed framework is empowered with ontologies and formalized using category theory to provide a deep and common understanding of the functional and nonfunctional requirement hierarchies and their interrelations, and to trace the effects of a change on the conceptual framework.

A Traceability Metamodel for Change Management of Non-functional Requirements

Requirements changes are an issue in the software development life cycle which often originates from an incomplete knowledge of the domain of interest. Hardly any requirement manifests in isolation, and usually the provision of one requirement may affect the level of provision of another. Understanding the relations among system requirements is essential to ensuring their consistency and change management. In practice, many organizations either focus their traceability efforts on functional requirements (FRs) or else fail entirely to implement an effective traceability process. Tracing non-functional requirements (NFRs) has, by and large, been neglected. In this paper, we propose a metamodel which explicitly captures NFRs and their relations, and which is independent from any programming paradigm. In addition, we present an implementation using XML-based representations for the metamodel and XQuery queries to represent tracing information.