Towards a modern quality framework

Quality frameworks have been used in requirements engineering (RE) for a long time to help elicit and document quality requirements. However, existing quality frameworks have major issues that hamper their applicability, particularly in RE, but also in other fields such as the design of digital systems. In this paper, we discuss the issues of existing quality frameworks and propose a new quality model, which has been designed for application as a quality framework in RE as well as in the design of digital systems. We present the rationale and requirements for our new model, introduce the model and sketch its application. Our work contributes to the improvement of quality frameworks used in RE and Digital Design.Peer ReviewedPostprint (published version

Lessons Learned from Developing a Sustainability Awareness Framework for Software Engineering using Design Science

[Context and Motivation] To foster a sustainable society within a sustainable environment, we must dramatically reshape our work and consumption activities, most of which are facilitated through software. Yet, most software engineers hardly consider the effects on the sustainability of the IT products and services they deliver. This issue is exacerbated by a lack of methods and tools for this purpose.[Question/Problem] Despite the practical need for methods and tools that explicitly support consideration of the effects that IT products and services have on the sustainability of their intended environments, such methods and tools remain largely unavailable. Thus, urgent research is needed to understand how to design such tools for the IT community properly.[Principal Ideas/Results] In this paper, we describe our experience using design science to create the Sustainability Awareness Framework (SusAF), which supports software engineers in anticipating and mitigating the potential sustainability effects during system development. More specifically, we identify and present the challenges faced during this process.[Contribution] The challenges that we have faced and addressed in the development of the SusAF are likely to be relevant to others who aim to create methods and tools to integrate sustainability analysis into their IT Products and Service development. Thus, the lessons learned in SusAF development are shared for the benefit of researchers and other professionals who design tools for that end

Managing Security Requirements Patterns using Feature Diagram Hierarchies

Abstract-Security requirements patterns represent reusable security practices that software engineers can apply to improve security in their system. Reusing best practices that others have employed could have a number of benefits, such as decreasing the time spent in the requirements elicitation process or improving the quality of the product by reducing product failure risk. Pattern selection can be difficult due to the diversity of applicable patterns from which an analyst has to choose. The challenge is that identifying the most appropriate pattern for a situation can be cumbersome and time-consuming. We propose a new method that combines an inquiry-cycle based approach with the feature diagram notation to review only relevant patterns and quickly select the most appropriate patterns for the situation. Similar to patterns themselves, our approach captures expert knowledge to relate patterns based on decisions made by the pattern user. The resulting pattern hierarchies allow users to be guided through these decisions by questions, which introduce related patterns in order to help the pattern user select the most appropriate patterns for their situation, thus resulting in better requirement generation. We evaluate our approach using access control patterns in a pattern user study

A concern-oriented sustainability approach

Sustainability and sustainable development has become a concern worldwide, hence introduced in roadmaps and strategies of public and private organizations. This trend has not been neglected by the computer science community, who is increasingly considering sustainability as a first class entity in software development. To properly address sustainability, its various dimensions need to be reasoned about and their impact on each other and on other system concerns studied from the very early stages of software development. To this purpose, we present a concern-oriented requirements approach that allows both, modeling sustainability concepts and their relationships, and managing conflicting situations triggered by impacts among sustainability dimensions or between those and other system concerns. To tackle the complexity of conflict management, a rigorous trade-off analysis technique based on multi-criteria decision making methods is used to rank, stakeholders and effects between concerns' responsibilies. We use a real project to validate our proposal, discuss the results obtained and synthesize major points that require further research

Contracts for Systems Design: Methodology and Application cases

Recently, contract based design has been proposed as an ”orthogonal” approach that can beapplied to all methodologies proposed so far to cope with the complexity of system design. Contract baseddesign provides a rigorous scaffolding for verification, analysis and abstraction/refinement. Companionreport RR-8759 proposes a unified treatment of the topic that can help in putting contract-based design in perspective.This paper complements RR-8759 by further discussing methodological aspects of system design withcontracts in perspective and presenting two application cases.The first application case illustrates the use of contracts in requirement engineering, an area of system designwhere formal methods were scarcely considered, yet are stringently needed. We focus in particular to thecritical design step by which sub-contracts are generated for suppliers from a set of different viewpoints(specified as contracts) on the global system. We also discuss important issues regarding certification inrequirement engineering, such as consistency, compatibility, and completeness of requirements.The second example is developed in the context of the Autosar methodology now widely advocated inthe automotive sector. We propose a contract framework to support schedulability analysis, a key step inAutosar methodology. Our aim differs from the many proposals for compositional schedulability analysisin that we aim at defining sub-contracts for suppliers, not just performing the analysis by parts—we knowfrom companion paper RR-8759 that sub-contracting to suppliers differs from a compositional analysis entirelyperformed by the OEM. We observe that the methodology advocated by Autosar is in contradiction withcontract based design in that some recommended design steps cannot be refinements. We show how tocircumvent this difficulty by precisely bounding the risk at system integration phase. Another feature ofthis application case is the combination of manual reasoning for local properties and use of the formalcontract algebra to lift a collection of local checks to a system wide analysis

Domain- and Quality-aware Requirements Engineering for Law-compliant Systems

Titel in deutscher Übersetzung: Domänen- und qualitätsgetriebene Anforderungserhebung für gesetzeskonforme Systeme Der bekannte Leitsatz in der Anforderungserhebung und -analyse besagt, dass es schwierig ist, das richtige System zu bauen, wenn man nicht weiß, was das 'Richtige' eigentlich ist. Es existieren überzeugende Belege, dass dieser Leitsatz die Notwendigkeit der Anforderungserhebung und -analyse exakt definiert und beschreibt. Zum Beispiel ergaben Studien, dass das Beheben von Defekten in einer Software, die bereits produktiv genutzt wird, bis zu 80 mal so teuer ist wie das frühzeitige Beheben der korrespondierenden Defekte in den Anforderungen. Generell hat es sich gezeigt, dass das Durchführen einer angemessenen Anforderungserhebung und -analyse ein wichtiger Erfolgsfaktor für Softwareentwicklungsprojekte ist. Während der Progression von den initialen Wünschen der beteiligten Interessensvertretern für ein zu entwickelndes System zu einer Spezifikation für eben dieses Systems müssen Anforderungsanalysten einen komplexen Entscheidungsprozess durchlaufen, der die initialen Wünsche in die Spezifikation überführt. Tatsächlich wird das Treffen von Entscheidungen als integraler Bestandteil der Anforderungsanalyse gesehen. In dieser Arbeit werden wir versuchen zu verstehen welche Aktivitäten und Information von Nöten sind, um eine fundierte Auswahl von Anforderungen vorzunehmen, welche Herausforderungen damit verbunden sind, wie eine ideale Lösung zur Anforderungswahl aussehen könnte und in welchen Bereichen der aktuelle Stand der Technik in Bezug auf diese ideale Lösung lückenhaft ist. Innerhalb dieser Arbeit werden wir die Informationen, die notwendig für eine fundierte Anforderungsauswahl sind, identifizieren, einen Prozess präsentieren, um diese notwendigen Informationen zu sammeln, die Herausforderungen herausstellen, die durch diesen Prozess und die damit verbundenen Aktivitäten adressiert werden und eine Auswahl von Methoden diskutieren, mit deren Hilfe man die Aktivitäten des Prozesses umsetzen kann. Die gesammelten Informationen werden dann für eine automatisierte Anforderungsauswahl verwendet. Für die Auswahl kommt ein Optimierungsmodell, das Teil des Beitrags dieser Arbeit ist, zum Einsatz. Da wir während der Erstellung dieser Arbeit zwei große Lücken im Stand der Technik bezüglich unseres Prozesses und der damit verbundenen Aktivitäten identifiziert haben, präsentieren wir darüber hinaus zwei neuartige Methoden für die Kontexterhebung und die Erhebung von rechtlichen Anforderungen, um diese Lücken zu schließen. Diese Methoden sind Teil des Hauptbeitrags dieser Arbeit. Unsere Lösung für der Erhebung des Kontext für ein zu entwickelndes System ermöglicht das Etablieren eines domänenspezifischen Kontextes unter Zuhilfenahme von Mustern für verschiedene Domänen. Diese Kontextmuster erlauben eine strukturierte Erhebung und Dokumentation aller relevanten Interessensvertreter und technischen Entitäten für ein zu entwickelndes System. Sowohl die Dokumentation in Form von grafischen Musterinstanzen und textuellen Vorlageninstanzen als auch die Methode zum Sammeln der notwendigen Informationen sind expliziter Bestandteil jedes Kontextmusters. Zusätzlich stellen wir auch Hilfsmittel für die Erstellung neuer Kontextmuster und das Erweitern der in dieser Arbeit präsentierten Kontextmustersprache zur Verfügung. Unsere Lösung für die Erhebung von rechtlichen Anforderungen basiert auch auf Mustern und stellt eine Methode bereit, welche es einem erlaubt, die relevanten Gesetze für ein zu erstellendes System, welches in Form der funktionalen Anforderungen bereits beschrieben sein muss, zu identifizieren und welche die bestehenden funktionalen Anforderungen mit den rechtlichen Anforderungen verknüpft. Diese Methode beruht auf der Zusammenarbeit zwischen Anforderungsanalysten und Rechtsexperten und schließt die Verständnislücke zwischen ihren verschiedenartigen Welten. Wir veranschaulichen unseren Prozess unter der Zuhilfenahme eines durchgehenden Beispiels aus dem Bereich der service-orientierten Architekturen. Zusätzlich präsentieren wir sowohl die Ergebnisse der Anwendung unseres Prozesses (bzw. Teilen davon) auf zwei reale Fälle aus den Bereichen von Smart Grids und Wahlsystemen, als auch alle anderen Ergebnisse der wissenschaftlichen Methoden, die wir genutzt haben, um unsere Lösung zu fundieren und validieren.The long known credo of requirements engineering states that it is challenging to build the right system if you do not know what right is. There is strong evidence that this credo exactly defines and describes the necessity of requirements engineering. Fixing a defect when it is already fielded is reported to be up to eighty times more expensive than fixing the corresponding requirements defects early on. In general, conducting sufficient requirements engineering has shown to be a crucial success factor for software development projects. Throughout the progression from initial stakeholders' wishes regarding the system-to-be to a specification for the system-to-be requirements engineers have to undergo a complex decision process for forming the actual plan connecting stakeholder wishes and the final specification. Indeed, decision making is considered to be an inherent part of requirements engineering. In this thesis, we try to understand which activities and information are needed for selecting requirements, which the challenges are, how an ideal solution for selecting requirements would look like, and where the current state of the art is deficient regarding the ideal solution. Within this thesis we identify the information necessary for an informed requirements selection, present a process in which one collects all the necessary information, highlight the challenges to be addressed by this process and its activities, and a selection of methods to conduct the activities of the process. All the collected information is then used for an automated requirements selection using an optimization model which is also part of the contribution of this thesis. As we identified two major gaps in the state of the art considering the proposed process and its activities, we also present two novel methods for context elicitation and for legal compliance requirements elicitation to fill the gaps as part of the main contribution. Our solution for context elicitation enables a domain-specific context establishment based on patterns for different domains. The context patterns allow a structured elicitation and documentation of relevant stakeholders and technical entities for a system-to-be. Both, the documentation in means of graphical pattern instances and textual template instances as well as the method for collecting the necessary information are explicitly given in each context pattern. Additionally, we also provide the means which are necessary to derive new context patterns and extend our context patterns language which is part of this thesis. Our solution for legal compliance requirements elicitation is a pattern-based and guided method which lets one identify the relevant laws for a system-to-be, which is described in means of functional requirements, and which intertwines the functional requirements with the according legal requirements. This method relies on the collaboration of requirements engineers and legal experts, and bridges the gap between their distinct worlds. Our process is exemplified using a running example in the domain of service oriented architectures. Additionally, the results of applying (parts of) the process to real life cases from the smart grid domain and voting system domain are presented, as well as all other results from the scientific means we took to ground and validate the proposed solutions