Requirements Prioritization Based on Benefit and Cost Prediction: A Method Classification Framework

In early phases of the software development process, requirements prioritization necessarily relies on the specified requirements and on predictions of benefit and cost of individual requirements. This paper induces a conceptual model of requirements prioritization based on benefit and cost. For this purpose, it uses Grounded Theory. We provide a detailed account of the procedures and rationale of (i) how we obtained our results and (ii) how we used them to form the basis for a framework for classifying requirements prioritization methods

Towards a scope management of non-functional requirements in requirements engineering

Getting business stakeholders’ goals formulated clearly and project scope defined realistically increases the chance of success for any application development process. As a consequence, stakeholders at early project stages acquire as much as possible knowledge about the requirements, their risk estimates and their prioritization. Current industrial practice suggests that in most software projects this scope assessment is performed on the user’s functional requirements (FRs), while the non-functional requirements (NFRs) remain, by and large, ignored. However, the increasing software complexity and competition in the software industry has highlighted the need to consider NFRs as an integral part of software modeling and development. This paper contributes towards harmonizing the need to build the functional behavior of a system with the need to model the associated NFRs while maintaining a scope management for NFRs. The paper presents a systematic and precisely defined model towards an early integration of NFRs within the requirements engineering (RE). Early experiences with the model indicate its ability to facilitate the process of acquiring the knowledge on the priority and risk of NFRs

Decision-making through sustainability

From immemorial time, dams have contributed significantly for the progress of civilizations. For this reason, nowadays, there is a vast engineering heritage. Over the years, these infrastructures can present some ordinary maintenance issues associated with their normal operation or with ageing processes. Normally, these problems do not represent an important risk for the structure, but they have to be attended. To do it, owners of dams have to finance many ordinary interventions. As it is impossible to carry out all of them at the same time, managers have to make a decision and select the most “important” ones. However, it is not easy because interventions usually have very different natures (for example: repair a bottom outlet, change gates, seal a crack...) and they cannot use a classical risk analysis for these type of interventions. The authors, who are aware this problem, present, in this paper, a multi-criteria decision-making system to prioritize these interventions with the aim of providing engineers a useful tool, with which they can prioritize the interventions from the most important to the least. To do it, the authors have used MIVES. This tool defines the Prioritization Index for the Management of Hydraulic Structures (PIMHS), which assesses, in two phases, the contribution to sustainability of each intervention. The first phase measures the damage of the dam, and the second measures the social, environmental and economic impacts. At the end of the paper, a case of study is presented where some interventions are evaluated with PIMHS.Postprint (published version

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

Technical Debt Prioritization: State of the Art. A Systematic Literature Review

Background. Software companies need to manage and refactor Technical Debt issues. Therefore, it is necessary to understand if and when refactoring Technical Debt should be prioritized with respect to developing features or fixing bugs. Objective. The goal of this study is to investigate the existing body of knowledge in software engineering to understand what Technical Debt prioritization approaches have been proposed in research and industry. Method. We conducted a Systematic Literature Review among 384 unique papers published until 2018, following a consolidated methodology applied in Software Engineering. We included 38 primary studies. Results. Different approaches have been proposed for Technical Debt prioritization, all having different goals and optimizing on different criteria. The proposed measures capture only a small part of the plethora of factors used to prioritize Technical Debt qualitatively in practice. We report an impact map of such factors. However, there is a lack of empirical and validated set of tools. Conclusion. We observed that technical Debt prioritization research is preliminary and there is no consensus on what are the important factors and how to measure them. Consequently, we cannot consider current research conclusive and in this paper, we outline different directions for necessary future investigations

Visualizing test diversity to support test optimisation

Diversity has been used as an effective criteria to optimise test suites for cost-effective testing. Particularly, diversity-based (alternatively referred to as similarity-based) techniques have the benefit of being generic and applicable across different Systems Under Test (SUT), and have been used to automatically select or prioritise large sets of test cases. However, it is a challenge to feedback diversity information to developers and testers since results are typically many-dimensional. Furthermore, the generality of diversity-based approaches makes it harder to choose when and where to apply them. In this paper we address these challenges by investigating: i) what are the trade-off in using different sources of diversity (e.g., diversity of test requirements or test scripts) to optimise large test suites, and ii) how visualisation of test diversity data can assist testers for test optimisation and improvement. We perform a case study on three industrial projects and present quantitative results on the fault detection capabilities and redundancy levels of different sets of test cases. Our key result is that test similarity maps, based on pair-wise diversity calculations, helped industrial practitioners identify issues with their test repositories and decide on actions to improve. We conclude that the visualisation of diversity information can assist testers in their maintenance and optimisation activities

DPN -- Dependability Priority Numbers

This paper proposes a novel model-based approach to combine the quantitative dependability (safety, reliability, availability, maintainability and IT security) analysis and trade-off analysis. The proposed approach is called DPN (Dependability Priority Numbers) and allows the comparison of different actual dependability characteristics of a systems with its target values and evaluates them regarding trade-off analysis criteria. Therefore, the target values of system dependability characteristics are taken as requirements, while the actual value of a specific system design are provided by quantitative and qualitative dependability analysis (FHA, FMEA, FMEDA, of CFT-based FTA). The DPN approach evaluates the fulfillment of individual target requirements and perform trade-offs between analysis objectives. We present the workflow and meta-model of the DPN approach, and illustrate our approach using a case study on a brake warning contact system. Hence, we demonstrate how the model-based DPNs improve system dependability by selecting the project crucial dependable design alternatives or measures

A new test framework for communications-critical large scale systems

None of today’s large scale systems could function without the reliable availability of a varied range of network communications capabilities. Whilst software, hardware and communications technologies have been advancing throughout the past two decades, the methods commonly used by industry for testing large scale systems which incorporate critical communications interfaces have not kept pace. This paper argues for the need for a specifically tailored framework to achieve effective and precise testing of communications-critical large scale systems (CCLSSs). The paper briefly discusses how generic test approaches are leading to inefficient and costly test activities in industry. The paper then outlines the features of an alternative CCLSS domain-specific test framework, and then provides an example based on a real case study. The paper concludes with an evaluation of the benefits observed during the case study and an outline of the available evidence that such benefits can be realized with other comparable systems