Types Of Non-functional Requirements Research Articles

Computing for Autonomy: Latency, Power, Resilience

The articles in this special section focus on the development of autonomous systems. This theme issue on computing for autonomy presents responsive and reliable computing for assured autonomy. Autonomous systems have emerged as a key technology for a wide range of use cases. They can be used to inspect remote equipment, deliver packages, and transport people. Types of autonomous vehicles include those that operate on the ground, under the ocean, in the air, and in space. An autonomous system may include multiple vehicles. Vehicles may operate in formation or in swarms to perform a task. They may also cooperate to avoid collisions and traffic jams. Computing for autonomy clearly requires support for artificial intelligence and the large computational load that applications imply. These systems must also satisfy several types of nonfunctional requirements. Assured autonomy requires real-time responsiveness. Real-time operation is not only necessary for correct and efficient operation but also is a requirement for the safe operation of autonomous systems across many application domains. Safety is fundamental to the acceptance

Mining Non-Functional Requirements using Machine Learning Techniques

Background: Non-Functional Requirements (NFR) have a direct impact on the architecture of the system, thus it is essential to identify NFRs in the initial phases of software development. Aim: The work is based on extraction of relevant keywords from NFR descriptions by employing text mining steps and thereafter classifying these descriptions into one of the nine types of NFRs. Method: For each NFR type, keywords are extracted from a set of pre-categorized specifications using Information-Gain measure. Then models using 8 Machine Learning (ML) techniques are developed for classification of NFR descriptions. A set of 15 projects (containing 326 NFR descriptions) developed by MS students at DePaul University are used to evaluate the models. Results: The study analyzes the performance of ML models in terms of classification and misclassification rate to determine the best model for predicting each type NFR descriptions. The Naïve Bayes model has performed best in predicting “maintainability” and “availability” type of NFRs. Conclusion: The NFR descriptions should be analyzed and mapped into their corresponding NFR types during the initial phases. The authors conducted cost benefit analysis to appreciate the advantage of using the proposed models.

Servicing Your Requirements: An FCA and RCA-Driven Approach for Semantic Web Services Composition

The evolution of Service-Oriented Computing (SOC) provides more efficient software development methods for building and engineering new value-added service-based applications. SOC is a computing paradigm that relies on Web services as fundamental elements. Research and technical advancements in Web services composition have been considered as an effective opportunity to develop new service-based applications satisfying complex requirements rapidly and efficiently. In this paper, we present a novel approach enhancing the composition of semantic Web services. The novelty of our approach, as compared to others reported in the literature, rests on: i) mapping user's/organization's requirements with Business Process Modeling Notation (BPMN) and semantic descriptions using ontologies, ii) considering functional requirements and also different types of non-functional requirements, such as quality of service (QoS), quality of experience (QoE), and quality of business (QoBiz), iii) using Formal Concept Analysis (FCA) technique to select the optimal set of Web services, iv) considering composability levels between sequential Web services using Relational Concept Analysis (RCA) technique to decrease the required adaptation efforts, and finally, v) validating the obtained service-based applications by performing an analytical technique, which is the monitoring. The approach experimented on an extended version of the OWLS-TC dataset, which includes more than 10830 Web services descriptions from various domains. The obtained results demonstrate that our approach allows to successfully and effectively compose Web services satisfying different types of user's functional and non-functional requirements.

Mining non-functional requirements from App store reviews

User reviews obtained from mobile application (app) stores contain technical feedback that can be useful for app developers. Recent research has been focused on mining and categorizing such feedback into actionable software maintenance requests, such as bug reports and functional feature requests. However, little attention has been paid to extracting and synthesizing the Non-Functional Requirements (NFRs) expressed in these reviews. NFRs describe a set of high-level quality constraints that a software system should exhibit (e.g., security, performance, usability, and dependability). Meeting these requirements is a key factor for achieving user satisfaction, and ultimately, surviving in the app market. To bridge this gap, in this paper, we present a two-phase study aimed at mining NFRs from user reviews available on mobile app stores. In the first phase, we conduct a qualitative analysis using a dataset of 6,000 user reviews, sampled from a broad range of iOS app categories. Our results show that 40% of the reviews in our dataset signify at least one type of NFRs. The results also show that users in different app categories tend to raise different types of NFRs. In the second phase, we devise an optimized dictionary-based multi-label classification approach to automatically capture NFRs in user reviews. Evaluating the proposed approach over a dataset of 1,100 reviews, sampled from a set of iOS and Android apps, shows that it achieves an average precision of 70% (range [66% - 80%]) and average recall of 86% (range [69% - 98%]).

Dealing with Non-Functional Requirements in Model-Driven Development: A Survey

Context: Managing Non-Functional Requirements (NFRs) in software projects is challenging, and projects that adopt Model-Driven Development (MDD) are no exception. Although several methods and techniques have been proposed to face this challenge, there is still little evidence on how NFRs are handled in MDD by practitioners. Knowing more about the state of the practice may help researchers to steer their research and practitioners to improve their daily work. Objective: In this paper, we present our findings from an interview-based survey conducted with practitioners working in 18 different companies from 6 European countries. From a practitioner's point of view, the paper shows what barriers and benefits the management of NFRs as part of the MDD process can bring to companies, how NFRs are supported by MDD approaches, and which strategies are followed when (some) types of NFRs are not supported by MDD approaches. Results: Our study shows that practitioners perceive MDD adoption as a complex process with little to no tool support for NFRs, reporting productivity and maintainability as the types of NFRs expected to be supported when MDD is adopted. But in general, companies adapt MDD to deal with NFRs. When NFRs are not supported, the generated code is sometimes changed manually, thus compromising the maintainability of the software developed. However, the interviewed practitioners claim that the benefits of using MDD outweight the extra effort required by these manual adaptations. Conclusion: Overall, the results indicate that it is important for practitioners to handle `NFRs in MDD, but further research is necessary in order to lower the barrier for supporting a broad spectrum of NFRs with MDD. Still, much conceptual and tool implementation work seems to be necessary to lower the barrier of integrating the broad spectrum of NFRs in practice.

Designing service-based applications in the presence of non-functional properties: A mapping study

ContextThe development of distributed software systems has become an important problem for the software engineering community. Service-based applications are a common solution for this kind of systems. Services provide a uniform mechanism for discovering, integrating and using these resources. In the development of service based applications not only the functionality of services and compositions should be considered, but also conditions in which the system operates. These conditions are called non-functional requirements (NFR). The conformance of applications to NFR is crucial to deliver software that meets the expectations of its users. ObjectiveThis paper presents the results of a systematic mapping carried out to analyze how NFR have been addressed in the development of service-based applications in the last years, according to different points of view. MethodOur analysis applies the systematic mapping approach. It focuses on the analysis of publications organized by categories called facets, which are combined to answer specific research questions. The facets compose a classification schema which is part of the contribution and results. ResultsThis paper presents our findings on how NFR have been supported in the development of service-based applications by proposing a classification scheme consisting in five facets: (i) programming paradigm (object/service oriented); (ii) contribution (methodology, system, middleware); (iii) software process phase; (iv) technique or mathematical model used for expressing NFR; and (v) the types of NFR addressed by the papers, based on the classification proposed by the ISO/IEC 9126 specification. The results of our systematic mapping are presented as bubble charts that provide a quantitative analysis to show the frequencies of publications for each facet. The paper also proposes a qualitative analysis based on these plots. This analysis discusses how NFR (quality properties) have been addressed in the design and development of service-based applications, including methodologies, languages and tools devised to support different phases of the software process. ConclusionThis systematic mapping showed that NFR are not fully considered in all software engineering phases for building service based applications. The study also let us conclude that work has been done for providing models and languages for expressing NFR and associated middleware for enforcing them at run time. An important finding is that NFR are not fully considered along all software engineering phases and this opens room for proposing methodologies that fully model NFR. The data collected by our work and used for this systematic mapping are available in https://github.com/placidoneto/systematic-mapping_service-based-app_nfr.

Extended Use Case for Specification of NFRs

The evolution of unified modelling language (UML) is absolutely required to make sure that UML will stay up to date with the latest developments in the software industry like modeling non-functional requirements (NFRs). In the past NFR literature many techniques have been identified that have used UML for modelling NFR. Because of great diversity in number and types of NFR it is difficult to be handled by common modelling techniques. So we think of extension of Use Case so that it can more effectively address the changing needs of many different classes of users and NFRs which further assists in specification and quantification of NFR.

A standards-based reference framework for system portability requirements

In the system requirements phase, the non-functional requirements (NFR) are often captured only generically at a fairly high level, and they do not yet include the levels of detail necessary for the system engineers to allocate them as specific functionalities to be handled either by the software or the hardware, or a specific combination of the two. The European ECSS series of standards for the aerospace industry includes portability requirements as one of sixteen types of non functional requirements (NFR) for embedded and real-time software. A number of portability-related concepts are dispersed throughout the ECSS, IEEE-830, ISO 9126, ISO 24765, and ISO 2382-1 standards to describe, at varying levels of detail, the various types of candidate portability requirements at the system, software, and hardware levels. This paper organizes these dispersed portability concepts and terms into a standards-based reference framework of system portability requirements. The availability of this framework can facilitate the early identification and specification of the system portability NFR and their detailed allocation as specific portability functions to be handled by the specified allocation to hardware or software, or a specific combination of the two. The approach selected in this research for the structure of this reference framework is based on the generic model of software proposed in the COSMIC-ISO 19761 model, thereby allowing the functional size of the portability requirements allocated to software to be measured.

A standards-based model of system maintainability requirements

SUMMARY The nonfunctional requirements (NFR) are often captured only generically at a fairly high level, and they do not include the levels of detail necessary at this stage for the system engineers to allocate them as specific functionalities to be handled either by the software or the hardware, or a specific combination of the two. The European Cooperation for Space Standardization (ECSS) series of standards for the aerospace industry includes maintainability requirements as one of 16 types of NFR for embedded and real-time software. A number of maintainability-related concepts are dispersed throughout the ECSS, ISO 9126, and Institute of Electrical and Electronics Engineers standards to describe, at varying levels of detail, the various types of candidate maintainability requirements at the system, software, and hardware levels. This paper organizes these dispersed maintainability concepts into a standards-based reference model of system maintainability requirements. The availability of this reference model can facilitate the early identification of the system maintainability-NFR and their detailed allocation as specific maintainability functions to be handled by the specified allocation to hardware or software, or a specific combination of the two. In the absence of such a reference model, these NFR are typically handled in practice much later on in the software development life cycle, when at system testing time, users and developers find out that a number of maintainability requirements have been overlooked and additional effort has to be expended to implement them. The approach adopted in this research for the structure of this reference NFR model is based on the generic model of software functional requirements proposed in the COSMIC – ISO 19761 model, thereby allowing the functional size of such maintainability requirements allocated to software to be measured. Copyright © 2012 John Wiley & Sons, Ltd.