Dealing with non-functional requirements in model-driven development

The impact of non-functional requirements (NFRs) over software systems has been widely documented. Consequently, cost-effective software production method shall provide means to integrate this type of requirements into the development process. In this vision paper we analyze this assumption over a particular type of software production paradigm: model-driven development (MDD). We report first the current state of MDD approaches with respect to NFRs and remark that, in general, NFRs are not addressed in MDD methods and processes, and we discuss the effects of this situation. Next, we outline a general framework that integrates NFRs into the core of the MDD process and provide a detailed comparison among all the MDD approaches considered. Last, we identify some research issues related to this framework.Preprin

A Systematic Classification and Analysis of NFRs

The main agenda of Requirements Engineering (RE) is the development of tools, techniques and languages for the elicitation, specification, negotiation, and validation of software requirements. However, this development has traditionally been focused on functional requirements (FRs), rather than non-functional requirements (NFRs). Consequently, NFR approaches developed over the years have been fragmental and there is a lack of clear understanding of the positions of these approaches in the RE process. This paper provides a systematic classification and analysis of 89 NFR approaches

Towards an Ontology-Based Approach for Reusing Non-Functional Requirements Knowledge

Requirements Engineering play a crucial role during the software development process. Many works have pointed out that Non-Functional Requirements (NFR) are currently more important than Functional Requirements. NFRs can be very complicated to understand due to its diversity and subjective nature. The NDR Framework has been proposed to fill some of the existing gaps to facilitate NFR elicitation and modeling. In this thesis, we introduce a tool that plays a major role in the NDR Framework allowing software engineers to store and reuse NFR knowledge. The NDR Tool converts the knowledge contained in Softgoal Interdependency Graphs (SIGs) into a machine-readable format that follows the NFR and Design Rationale (NDR) Ontology. It also provides mechanisms to query the knowledge base and produces graphical representation for the results obtained. To evaluate whether our approach aids eliciting NFRs, we conducted an experiment performing a software development scenario

Development of service-oriented architectures using model-driven development : a mapping study

Context: Model-Driven Development (MDD) and Service-Oriented Architecture (SOA) are two challenging research areas in software engineering. MDD is about improving software development whilst SOA is a service-based conceptual development style, therefore investigating the available proposals in the literature to use MDD when developing SOA may be insightful. However, no studies have been found with this purpose. Objective: This work aims at assessing the state of the art in MDD for SOA systems. It mainly focuses on: what are the characteristics of MDD approaches that support SOA; what types of SOA are supported; how do they handle non-functional requirements. Method: We conducted a mapping study following a rigorous protocol. We identified the representative set of venues that should be included in the study. We applied a search string over the set of selected venues. As result, 129 papers were selected and analysed (both frequency analysis and correlation analysis) with respect to the defined classification criteria derived from the research questions. Threats to validity were identified and mitigated whenever possible. Results: The analysis allows us to answer the research questions. We highlight: (1) predominance of papers from Europe and written by researchers only; (2) predominance of top-down transformation in software development activities; (3) inexistence of consolidated methods; (4) significant percentage of works without tool support; (5) SOA systems and service compositions more targeted than single services and SOA enterprise systems; (6) limited use of metamodels; (7) very limited use of NFRs; and (8) limited application in real cases. Conclusion: This mapping study does not just provide the state of the art in the topic, but also identifies several issues that deserve investigation in the future, for instance the need of methods for activities other than software development (e.g., migration) or the need of conducting more real case studies.Peer ReviewedPostprint (author's final draft

Relational-model based change management for non-functional requirements: approach and experiment

In software industry, many organizations either focus their traceability efforts on Functional Requirements (FRs) or else fail entirely to implement an effective traceability process. NonFunctional Requirements (NFRs) such as security, safety, performance, and reliability are treated in a rather ad hoc fashion and are rarely traced. This is mainly because of the unique nature of NFRs. They are subjective, relative and they tend to become scattered among multiple modules when they are mapped from the requirements domain to the solution space. Furthermore, NFRs can often interact, in the sense that attempts to achieve one NFR can help or hinder the achievement of other NFRs at particular software functionality. Such an interaction creates an extensive network of interdependencies and tradeoffs among NFRs which is not easy to trace. In a previous work, we proposed a conceptualization of NFRs through the NFRs Ontology. In this paper, we extend the previous work by proposing a change management mechanism for tracing the impact of NFRs on the other constructs in the ontology such as FR or NFR operationalization and vice versa, and providing a traceability mechanism using Datalog expressions to imp lement queries on a relational model-based representation for the ontology. The proposed traceability queries are then evaluated through a multiproject variation quasi-experiment on regression testing conducted in the industry

Analyzing Requirement Type Influence on Generated Solutions

Several ideation methods are available and used by engineering designers to enable the generation of alternative designs [1]. However, there has been little work done to understand the role that the design problem given to participants plays in the ideation process. The contribution of this research is found through the proposed guidelines with respect to the type of requirements to include as part of the design problem in order to achieve the desired quantity, quality, novelty, and variety of solutions during the early stages of the design process. This work is the first attempt at analyzing the effect of requirement type on the solutions generated to a design problem. A user study is conducted with undergraduate mechanical engineering students to test the hypothesis that functional requirements lead to better understanding of the design problem, and thereby to improved ideation with respect to the quality, quantity, novelty, and variety scores on the solution sets. All the participants were given a burrito folder design problem and asked to generate solutions. The four experimental conditions were functional requirements, non-functional requirements, mixed prioritized requirements, and non-prioritized requirements. This study used a standard set of outcome based measures for ideation: quantity, quality, novelty and variety [1]. The findings reveal that non-functional requirements are useful in ideation to achieve a greater quantity of solution (p-value=0.09) and better quality of solutions (p-value=0.018). It also shows that non-functional requirements positively impact the variety and novelty of solutions. In addition, the mixed requirements groups achieve a better variety than the functional requirements groups. The results highlight potential improvements that might be achieved by using non-functional requirements in ideation. Therefore it is recommended that designers explore these non-functional requirements of a problem, a recommendation that does not align with current best practice design education as seen through a review of popular design engineering text books. These findings lead to areas for future research in understanding how the functionality of requirements influence an engineer’s thinking

Ranking the Azorean Natural Forest Reserves for conservation using their endemic arthropods

Copyright © 2000 Kluwer Academic Publishers.Endemic arthropods were used to evaluate the conservation value of the 16 Natural Forest Reserves (NFRs) of the Azores (Macaronesia). For each of the 280 known Azorean endemic species of arthropods, a rarity index was calculated, using distribution and abundance data obtained from the literature. In addition, several scoring indices were used to rank the 16 NFRs. Frequency distributions of the rarity index indicated that there was a tendency for a greater proportion of the commonest species being represented in the NFRs in contrast with a lower representation of the rarest species. About 60% of the endemic arthropod species that were recorded from the NFRs are single NFR endemics , that is, are known from only one of the 16 NFRs. Species richness was considered to be a very good surrogate measure of the conservation value of the 16 NFRs under study. The fact that the six highest ranked NFRs (using a composite multi-criteria index) are located in different islands has some important conservation management implications; to preserve a large proportion of the Azorean arthropod biodiversity there is a need to protect sites in all islands. If the five highest ranked NFRs are correctly managed in terms of conservation, then at least 80% of the endemic arthropods known from the NFRs could be protected. Most of the tested taxa (Acari-Oribatei; Lepidoptera; Diptera; Coleoptera) are good surrogates of the overall total set of species present in the 16 NFRs when using a species richness index

Assisting software architects in architectural decision-making using Quark

Non-Functional Requirements (NFRs) and constraints are among the principal drivers of architectural decision-making. NFRs are improved or damaged by architectural decisions (ADs), while constraints directly include or exclude parts of the architecture (e.g., logical components or technologies). We may determine the impact of an AD, or which parts of the architecture are affected by a constraint, but at the end it is hard to know if we are respecting the NFRs and the imposed constraints with all the ADs made. In the usual approach, architects use their own experience to produce software architectures that comply with the NFRs and imposed constraints, but at the end, especially for crucial decisions, the architect has to deal with complex trade-offs between NFRs and juggle with possible incompatibilities raised by the imposed constraints. In this paper we present Quark, a method to assist software architects in architectural decision-making, and the conceptualization of the relationship between NFRs and ADs defined in Arteon, an ontology to represent and manage architectural knowledge. Finally, we provide an overview of the Quark and Arteon implementation, the ArchiTech tool.Peer ReviewedPostprint (published version