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The ‘plastisphere’, the diverse microbial community growing on the surface of floating plastic debris, represents a new artificial habitat for drifting aquatic organisms. Despite the presence of microalgae within this epiplastic biofilm has been documented, it is still unclear how these materials influence the structure and dynamics of microalgae communities, in particular in freshwater ecosystems. Here, we present the first results of the 4th collaborative FreshProject "PhytoPlastic". The project is aimed at investigating the temporal establishment of phytobenthos on different plastic polymers in lakes over a wide geographical scale. We incubated two widely used plastic polymers (low-density polyethylene-LDPE, polyethylene terephthalate-PET) and glass substrates (as control) in 14 lakes across Europe. To assess the temporal and seasonal evolution of the colonisation, samples were collected in each season after 3, 7, 15, and 30 days. For each substrate, we assessed the phytobenthic biomass estimating the chlorophyll a, and the ash-free dry mass. Moreover, microalgae composition was taxonomically determined on a subset of samples. This project represents, to the best of our knowledge, the first coordinated experiment conducted at a large spatial scale that explores the microalgae-plastic interaction. We will thereby generate a unique dataset, providing additional knowledge about the key drivers of the processes involved. Besides the valuable scientific knowledge, the project represents a large collaboration among early career researchers in freshwater sciences and will set the basis for further partnerships.

As researchers and teachers and practitioners, we "software types" excel at multitasking. This, in part, led us to ask the question: Can one attend a software engineering conference and do something good for society? We found the answer to be a resounding yes. In this article, we present our first experience of running RE Cares, a conference collocated event. This event included a workshop, conference sessions, and a hackathon for developing an application to support emergency field activity for Mutual Aid Alberta, a nonprofit organization coordinating natural disaster responses in the Canadian province.

Since the 1980s, requirements engineering (RE) for information systems has been performed in practice using techniques (rather than the full method) from Information Engineering (IE) such as business goal analysis, function{ and process modeling, and cluster analysis. Recently, these techniques have been supplemented with portfolio management, which looks at sets of IT projects and offers fast quantitative decision-making about continuation of IT projects. Today's networked world, though, poses challenges to these techniques. A major drawback is their inability to adequately specify the requirements for IT systems used by businesses that provide services to each other in a value web. In this paper, we analyze this problem, and propose a solution by coupling IE and portfolio management with value-based RE techniques at the business network level. We show how these techniques interrelate, and illustrate our approach with a small example.

This paper presents a two-site case study on requirements-based effort estimation practices in enterprise resource planning projects. Specifically, the case study investigated the question of how to handle qualitative data and highly volatile values of project context characteristics. We counterpart this challenge and expound upon the integration of portfolio management concepts and simulation concepts into a classic effort estimation model (COCOMO II).

In the current practice of designing software for user organizations, as experienced by the authors, designers often produce design knowledge again and again for every decision: They re-invent the wheel. We want to improve the quality, predictability and efficiency of the software design process by reusing design knowledge. Our proposed solution consists of Reusable Rationale Blocks (RRBs). An RRB is a schema and a notation to write down decision rationale. To manage RRBs, we introduce a generalized design space, that consists of a collection of RRBs. And to use RRBs, we define a process that can be added to any design process, as well as a set of heuristics to be used in applying this process. We illustrate our solution by a few examples taken from our own experience.

69 pp. (2004)., The special interest group on requirements engineering of the German Informatics Society has established a working group on “Requirements Engineering Patterns”. The group has demonstrated the applicability of the concept of patterns for collecting and exchanging re- quirements engineering (RE) experience, especially for project teams which are in the process of adopting RE. This report presents an overview of the work and a summary of the results of the working group. It describes a method for comparing case studies and extracting patterns of recurring successful requirements engineering activities, and it contains a catalogue of fourteen RE patterns which have been identified by that method. A Web-based RE pattern repository is being developed to make patterns available for project teams on the job.

Dieser Artikel beschreibt, wie nichtfunktionale Anforderungen verfeinert und messbar beschrieben werden können. Dabei werden einerseits Abhängigkeiten zu funktionalen Anforderungen und der Architektur explizit gemacht. Andererseits werden Erfahrungen aus bereits durchgeführten Projekten in Form von Verfeinerungsgraphen und Checklisten genutzt.

The requirements specification - as outcome of the requirements engineering process - falls short of capturing other useful information generated during this process, such as the justification for selected requirements, trade-offs negotiated by stakeholders and alternative requirements that were discarded. In the context of evolving systems and distributed development, this information is essential. Rationale methods focus on capturing and structuring this missing information. In this paper, we propose an integrated process with dedicated guidance for capturing requirements and their rationale, discuss its tool support and describe the experiences we made during several case studies with students. Although the idea of integrating rationale methods with requirements engineering is not new, few research projects so far have focused on smooth integration, dedicated tool support and detailed guidance for such methods.

Informations- und Kommunikationstechnologie prägen zunehmend unsere Wirtschaft und Gesellschaft. Ihre weite Verbreitung erfordert eine Softwareentwicklung, die nicht nur auf die Technologie, sondern auch auf die Besonderheiten der Anwendungsgebiete ausgerichtet ist. Das vorliegende Buch behandelt die Gestaltung von Softwaresystemen und ihren Umgebungszusammenhängen mit der Methode der Objekt- und Aufgabenorientierten Software-Entwicklung (OASE). Der Vorstellung der wesentlichen Konzepte folgt eine systematische Darstellung der vorhandenen Modellierungstechniken. Typische Methoden aus der Betriebswirtschaft, den Sozial- und Arbeitswissenschaften, der Softwareergonomie und des Software Engineering werden daraufhin untersucht, welchen Beitrag sie zur integrierten Modellierung und Gestaltung von Softwaresystemen leisten. OASE greift wesentliche Elemente dieser Methoden auf und vervollständigt sie zu einer durchgängigen Modellierung eines Anwendungs-, Nutzungs- und Softwaresystems.