Towards an Artifact Model for Requirements to IT-enabled Product Service Systems

The development of IT-enabled product service systems (PSS) – a combination of physical technological elements (products) and service elements – poses various challenges because of their complexity and the involvement of multiple domains. Classical requirements engineering (RE) addresses these problems only insufficiently. This paper proposes an artifact model for the requirements to PSS, which helps in overcoming these problems. The results generated by RE or the development activities are called artifacts. The artifact model defines different types of artifacts and their interrelations. This provides a structure which facilitates the handling of a large number of requirements. The applicability of the presented artifact model is demonstrated in an example where the artifact model is applied to a real-life product. We show that the requirements can be modeled using the artifact model, and that common problems of RE can be avoided in this way

Towards an Artifact-Oriented Requirements Engineering Model for Developing Successful Products, Services, and Systems: Identification of Model Requirements

Despite extensive research in the domain of requirements engineering (RE), companies still struggle with this discipline. Moreover, practitioners are challenged with developing successful products, services, and systems which address the true needs of their customers. This gives rise to a new research field in the domain of RE, namely artifact orientation. According to the literature, this artifact orientation should increase the success of RE significantly. By conducting a literature review and 7 expert interviews, we identified 7 model requirements (MRs) for an artifact-oriented RE model. Furthermore, the results of this paper suggest that existing artifact-oriented RE models do not sufficiently address all identified MRs. In particular, these models lack the combination of traditional RE practices, such as goal orientation, documentation, and traceability with novel agile approaches. Furthermore, there is a need for a more holistic RE which merges the domains of product, service, and software engineering

An Integrated View of Data: Application of Knowledge Modeling to Data Management

Data management has become an important challenge. Good data management requires an effective approach to collecting, storing, and accessing data across the enterprise. In this paper, a knowledge modeling approach to data management is introduced with an emphasis on data requirements analysis. A knowledge model can provide a high-level view of organizational data by specifying the structure and relationships of the knowledge contents used in business processes. The proposed knowledge modeling approach is business process oriented and decision oriented. The description of the knowledge contents in the model is based on ontological specification. The model is comprised of five elements: work product, work unit, producer, stage, and modeling language. The elements of the model and the modeling process are elaborated. The proposed modeling approach is applied to the vessel chartering process in a shipping company to demonstrate its application in real-world practices

Requirements engineering for explainable systems

Information systems are ubiquitous in modern life and are powered by evermore complex algorithms that are often difficult to understand. Moreover, since systems are part of almost every aspect of human life, the quality in interaction and communication between humans and machines has become increasingly important. Hence the importance of explainability as an essential element of human-machine communication; it has also become an important quality requirement for modern information systems. However, dealing with quality requirements has never been a trivial task. To develop quality systems, software professionals have to understand how to transform abstract quality goals into real-world information system solutions. Requirements engineering provides a structured approach that aids software professionals in better comprehending, evaluating, and operationalizing quality requirements. Explainability has recently regained prominence and been acknowledged and established as a quality requirement; however, there is currently no requirements engineering recommendations specifically focused on explainable systems. To fill this gap, this thesis investigated explainability as a quality requirement and how it relates to the information systems context, with an emphasis on requirements engineering. To this end, this thesis proposes two theories that delineate the role of explainability and establish guidelines for the requirements engineering process of explainable systems. These theories are modeled and shaped through five artifacts. These theories and artifacts should help software professionals 1) to communicate and achieve a shared understanding of the concept of explainability; 2) to comprehend how explainability affects system quality and what role it plays; 3) in translating abstract quality goals into design and evaluation strategies; and 4) to shape the software development process for the development of explainable systems. The theories and artifacts were built and evaluated through literature studies, workshops, interviews, and a case study. The findings show that the knowledge made available helps practitioners understand the idea of explainability better, facilitating the creation of explainable systems. These results suggest that the proposed theories and artifacts are plausible, practical, and serve as a strong starting point for further extensions and improvements in the search for high-quality explainable systems

A requirements data model for product service systems

Product service systems (PSS) are bundles of physical technological elements and service elements that are integrated to solve customer problems. In practice, most components of PSS are developed independently from each other, which leads to problems with coordination of development activities and integration of PSS components. Therefore, an integrated requirements engineering for PSS is needed that deals with the involvement of developers from product engineering, software engineering, and service engineering, as well as the inherent complexity of the PSS and the development process. In a case study with the development department of a PSS provider, we analyzed requirements documents and conducted expert interviews. We identified problems in the development, for example, that requirements on different levels of abstraction are intermingled, rationales for requirements are missing, and the concretization of requirements is unclear. To solve these problems, we propose a requirements data model (RDMod) for requirements to PSS. An RDMod describes different types of requirements and the relations between them. Thus, it is a scheme for the concretization of the requirements, which especially addresses the problems of structuring the requirements, enabling traceability, and finding conflicts. We then used an analytical evaluation, a feature-based evaluation and a retrospective application with requirements analysts of the industry partner. In a joint workshop, we specified requirements for a PSS with the RDMod. In structured interviews, we analyzed the perceived advantages of the RDMod. The experts confirmed that the RDMod is applicable in their development and it provides a clear structure for the requirements and therefore helps overcoming the identified problems

Field study on requirements engineering: investigation of artefacts, project parameters, and execution strategies

Context Requirements Engineering (RE) is a critical discipline mostly driven by uncertainty, since it is influenced by the customer domain or by the development process model used. Volatile project environments restrict the choice of methods and the decision about which artefacts to produce in RE. Objective We aim to investigate RE processes in successful project environments to discover characteristics and strategies that allow us to elaborate RE tailoring approaches in the future. Method We perform a field study on a set of projects at one company. First, we investigate by content analysis which RE artefacts were produced in each project and to what extent they were produced. Second, we perform qualitative analysis of semi-structured interviews to discover project parameters that relate to the produced artefacts. Third, we use cluster analysis to infer artefact patterns and probable RE execution strategies, which are the responses to specific project parameters. Fourth, we investigate by statistical tests the effort spent in each strategy in relation to the effort spent in change requests to evaluate the efficiency of execution strategies. Results We identified three artefact patterns and corresponding execution strategies. Each strategy covers different project parameters that impact the creation of certain artefacts. The effort analysis shows that the strategies have no significant differences in their effort and efficiency. Conclusions In contrast to our initial assumption that an increased effort in requirements engineering lowers the probability of change requests or project failures in general, our results show no statistically significant difference between the efficiency of the strategies. In addition, it turned out that many parameters considered as the main causes for project failures can be successfully handled. Hence, practitioners can apply the artefact patterns and related project parameters to tailor the RE process according to individual project characteristics

Goal-oriented business process engineering

Service-orientierte Architekturen haben sich als Architekturstil für die Entwicklung von Geschäftsanwendungen etabliert. Dementsprechend spielen Geschäftsprozessmodelle eine zentrale Rolle sowohl für die Beschreibung fachlicher Anforderungen als auch für die Spezifikation der erforderlichen Service-Kompositionen. Die modellierten Geschäftsprozesse dienen in der Regel keinem Selbstzweck, sondern der Erreichung eines strategischen Geschäftsziels. Um die Angemessenheit der Geschäftsprozessmodelle, zum Beispiel hinsichtlich ihrer Vollständigkeit und Relevanz, zu bewerten, müssen ihre Beziehungen und Abhängigkeiten zu den Unternehmensziele berücksichtigt werden.In bestehenden Arbeiten gibt es keine integrierte und durchgängige Spezifikationsmethode, die die zielorientierte Spezifikation, die systematische Ableitung von Geschäftsprozessmodellen und die Sicherstellung der Qualität ausreichend berücksichtigt. In dieser Arbeit wird ein Ansatz zur zielorientierten Spezifikation von Geschäftsprozessen vorgestellt, der Modellierungstechniken und Qualitätsanalysefunktionen beinhaltet. Basierend auf einer vorhandenen Ziebeschreibungssprache wird ein erweiterter Modellierungsansatz vorgestellt, der die Beschreibung von Abhängigkeiten zwischen Geschäftszielen und relevanten Elementen im Geschäftskontext sowie die Identifikation von komponierbaren Aktionen unterstützt. In einem systematischen Ableitungsverfahren wird beschrieben, wie diese Informationen bei der Komposition eines Geschäftsprozesses berücksichtigt werden können. Die Qualität der Spezifikation wird durch verschiedene Analyseverfahren sichergestellt.Service-oriented architectures have emerged as an architectural style for the design of business applications. Accordingly, business process models play a central role in the description of business requirements as well as in the specification of required service compositions.The modeling of business processes is not pursued for its own sake, but contributes to the achievement of strategic concerns represented by business goals. In order to evaluate the suitability of business process models, e.g. with respect to completeness and relevance, their relations to business goals need to be considered. This comprises the initial specification of business goals and business processes as well as the preservation of consistency between evolving models.In previous work, several goal-oriented requirements engineering approaches and business process modeling techniques have been proposed. Nonetheless, there is no integrated specification method that supports the goal-oriented specification, the systematic derivation of business process models and the assurance of quality in a sufficient manner.In this thesis, we present an approach for goal-oriented business process engineering that provides modeling techniques and analysis capabilities to assure the overall specification quality. Based on an existing goal-modeling notation, we introduce an extended modeling approach that supports the expression of goal dependencies, relevant business context elements and the identification of composable actions. Further, we describe a systematic derivation method to ensure the consideration of this information in the business process composition. To ensure a valid and consistent specification, a quality analysis and assurance framework is introduced.Tag der Verteidigung: 04.05.2015Paderborn, Univ., Diss., 201