Managing conflicts among non-functional requirements

Abstractâ Non-functional requirements (NFRs) tend to interfere, conflict, and contradict with one other. Unlike functional requirements, this inevitable conflict arises as a result of inherent contradiction among various types of NFRs. A number of techniques to deal with this conflict have been developed. Majority of them focus on categorizing, documenting, or listing the potential conflicts among NFRs. Several models that represent the positive or negative relationships among NFRs have also been published in literature. However, the interpretation of NFRs may vary depending on numerous factors, such as the context of the system being developed and stakeholder involvement. Consequently, the relationships among them are not always obvious. This paper investigates the gaps in the existing research literature about the conflicts among NFRs and proposes a framework to manage this type of conflict

Constructing a Catalogue of Conflicts among Non-functional Requirements

Non-Functional Requirements (NFRs) are recognized as a critical factor to the success of software projects because they address the essential issue of software quality. NFRs tend to interfere, conflict, and contradict with one another and this conflict is widely acknowledged as one of the key characteristics of NFRs. Several models of NFRs conflicts have been proposed and the interacting nature of NFRs has been characterized as either positive or negative inter-relationships among NFRs. Positive relationship represents a pair of NFRs that are supporting each other while negative relationship represents those NFRs that are conflicting with one another. Furthermore, as NFRs are also relative, the interpretation of NFRs may vary depending on many factors such as the context of the system being developed and the extent of stakeholders' involvement. The multiple interpretations of NFRs may lead to positive or negative inter-relationships that are not always obvious. These relationships may change depending on the meaning of NFRs in the system being developed. Hence, the existing potential conflicts models remain in disagreement with one other. This paper presents the result of an extensive and systematic investigation of the extant literature over the notion of NFRs and the conflicts among them. Rigorous synthesis of the carefully reviewed literature has resulted in the construction of a catalogue of NFRs conflicts with respect to NFRs relative characteristic. The relativity of conflicts is characterized by three categories: absolute conflict; relative conflict; and never conflict. This comprehensive catalogue could assist software developers with identifying the NFRs conflicts, performing conflicts analysis, and suggesting potential strategies to resolve these conflicts. © Springer-Verlag Berlin Heidelberg 2011

Utilizing TOPSIS: A Multi Criteria Decision Analysis Technique for Non-Functional Requirements Conflicts

Experience shows that many software systems suffer from inherent conflict among Non-Functional Requirements (NFRs). It also confirms that resolution strategies for handling NFRs conflicts often result in changing overall design guidelines, not by simply changing one module. Therefore, in software system development, software developers need to analyse the NFRs and conflicts among them in order to make decisions about alternative design solutions. This paper presents the use of Multi Criteria Decision Analysis (MCDA) approach for NFRs conflict decision analysis. TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), as one of the essential MCDA techniques has been adopted to resolve such conflict. We show how the systematic application of TOPSIS can assist software developers select the most preferable design solutions with respect to the conflicting NFRs. The quantitative result generated with this technique will be used as the basis for decision support. An example that shows the application of TOPSIS is also presented. © Springer-Verlag Berlin Heidelberg 2014

A comparison of software quality characteristics and software sustainability characteristics

Software sustainability has generated much interest in the software engineering field in recent times, and has been widely investigated across different fields and from different standpoints. The relationship between software quality and software sustainability is still an open question. In this study, a literature survey and comparison was conducted using three-phases, having as a starting point the comparison of basic models for software quality. A follow-up study, conducted at a more comprehensive level to cover both basic models and the most cited tailored models., Software sustainability literature is investigated to find the most frequent characteristics. Finally, data gathered from these studies and a comparison shows a similarity in the top level of these characteristics between software sustainability and software quality, and the emphasis on sustainability, maintainability and portability. The study suggests that ISO 25010 can be utilised by software sustainability. As a future work, the findings will be investigated empirically to support designing software sustainability framework identifying the most important criteria in the technical dimension.</div