Exploiting a Goal-Decomposition Technique to Prioritize Non-functional Requirements

Business stakeholders need to have clear and realistic goals if they want to meet commitments in application development. As a consequence, at early stages they prioritize requirements. However, requirements do change. The effect of change forces the stakeholders to balance alternatives and reprioritize requirements accordingly. In this paper we discuss the problem of priorities to non-functional requirements subjected to change. We, then, propose an approach to help smooth the impact of such changes. Our approach favors the translation of nonoperational specifications into operational definitions that can be evaluated once the system is developed. It uses the goal-question-metric method as the major support to decompose non-operational specifications into operational ones. We claim that the effort invested in operationalizing NFRs helps dealing with changing requirements during system development. Based on\ud this transformation and in our experience, we provide guidelines to prioritize volatile non-functional requirements

Scope Management of Non-Functional Requirements

In order to meet commitments in software projects, a realistic assessment must be made of project scope. Such an assessment relies on the availability of knowledge on the user-defined project requirements and their effort estimates and priorities, as well as their risk. This knowledge enables analysts, managers and software engineers to identify the most significant requirements from the list of requirements initially defined by the user. In practice, this scope assessment is applied to the Functional Requirements (FRs) provided by users who are unaware of, or ignore, the Non-Functional Requirements (NFRs). This paper presents ongoing research which aims at managing NFRs during the software development process. Establishing the relative priority of each NFR, and obtaining a rough estimate of the effort and risk associated with it, is integral to the software development process and to resource management. Our work extends the taxonomy of the NFR framework by integrating the concept of the "hardgoal". A functional size measure of NFRs is applied to facilitate the effort estimation process. The functional size measurement method we have chosen is COSMICFFP, which is theoretically sound and the de facto standard in the software industry

Towards a Solution Proposal to Agile Quality Requirements Challenges in Large-scale Projects

Over the years, the growth in usage of agile approaches in large-scale and distributed projects revealed the range of possible challenges experienced by organizations on their agile transformation journey. This short paper is focused on one particular type of challenges, namely those concerning the quality requirements (QRs) in agile large-scale projects. Leveraging previously published empirical results on QRs challenges in this context, the present paper makes a proposal for a solution. Using Design Science research methodology, we propose the Agile Quality Requirements Elaboration (AQRE) approach which introduces (1) a new organizational role and (2) a two-step process to elaborate high-level goal(s) into epics and user stories alongside with QRs. The fitness and the usefulness of AQRE will be empirically evaluated as part of our future work.</p

Agile Quality Requirements Elaboration:A Proposal and Evaluation

The increasing success and user satisfaction of agile methods’ application in their original context (eg small co-located teams), motivated large organizations to utilize agile methods to deal with the rapidly changing markets and the distributed global workforce. Several studies have reported a variety of quality requirements (QRs) challenges in large-scale distributed agile (LSDA) context, so a recent empirical study has identified 15 QRs challenges in LSDA projects. This paper proposes an approach based on the concept of goal documentation to deal with the 15 QRs challenges reported previously. Our proposal, the Agile Quality Requirements Elaboration (AQRE) approach, introduces a new organizational role and a two-step process to elaborate high-level goals (s) into epics and user stories alongside QRs. The fitness and the usefulness of AQRE are evaluated by using a focus group with eight practitioners in the IT department of a large Dutch government organization. The evaluation indicated that 12 of the 15 QRs challenges could be mitigated by the AQRE. Our main contribution is two-fold,(i) we proposed a solution approach to deal with QRs challenges in LSDA context, and (ii) our evaluation provided empirical evidence about its usefulness in realworld context

Exploiting a Goal-Decomposition Technique to Prioritize Non-functional Requirements

Business stakeholders need to have clear and realistic goals if they want to meet commitments in application development. As a consequence, at early stages they prioritize requirements. However, requirements do change. The effect of change forces the stakeholders to balance alternatives and reprioritize requirements accordingly. In this paper we discuss the problem of priorities to non-functional requirements subjected to change. We, then, propose an approach to help smooth the impact of such changes. Our approach favors the translation of nonoperational specifications into operational definitions that can be evaluated once the system is developed. It uses the goal-question-metric method as the major support to decompose non-operational specifications into operational ones. We claim that the effort invested in operationalizing NFRs helps dealing with changing requirements during system development. Based on this transformation and in our experience, we provide guidelines to prioritize volatile non-functional requirements. 1

Formal and quantitative approach to non-functional requirements modeling and assessment in software engineering

In the software market place, in which functionally equivalent products compete for the same customer, Non Functional Requirements (NFRs) become more important in distinguishing between the competing products. However, in practice, NFRs receive little attention relative to Functional Requirements (FRs). This is mainly because of the nature of these requirements which poses a challenge when taking the choice of treating them earlier in the software development. NFRs are subjective, relative and they 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 or estimate. This thesis contributes towards achieving the goal of managing the attainable scope and the changes of NFRs. The thesis proposes and empirically evaluates a formal and quantitative approach to modeling and assessing NFRs. Central to such an approach is the implementation of the proposed NFRs Ontology for capturing and structuring the knowledge on the software requirements (FRs and NFRs), their refinements, and their interdependencies. In this thesis, we also propose a change management mechanism for tracing the impact of NFRs on the other constructs in the ontology and vice-versa. We provide a traceability mechanism using Datalog expressions to implement queries on the relational model-based representation for the ontology. An alternative implementation view using XML and XQuery is provided as well. In addition, we propose a novel approach for the early requirements-based effort estimation, based on NFRs Ontology. The effort estimation approach complementarily uses one standard functional size measurement model, namely COSMIC, and a linear regression techniqu