Eva Kern

How to measure energy-efficiency of software: metrics and measurement results

In the field of information and computer technology (ICT), saving energy has its focus set on energy efficient hardware and its operation. Recently, efforts have also been made in the area of computer software. However, the development of energy efficient software requires metrics, which measure the softwares energy consumption as well as models to monitor and minimize it. In software and software development processes they hardly exist. In this work we present a generic metric to measure software and a method to apply it in a software engineering process.

Green software engineering with agile methods

The energy consumption of information and communication technology (ICT) is still increasing. Since several concepts regarding hardware solutions for Green IT exist, the contribution of software to Green IT is still not well investigated. This comprises the production and the usage impact of software on energy consumption. In our paper, we discuss this contribution. Especially, we present a model that integrates Green IT aspects into software engineering processes with agile methods in order to produce “greener” software from scratch.

Sustainable Software Engineering: Process and Quality Models, Life Cycle, and Social Aspects

Sustainability intersects Information and Communication Technology in two domains: Green IT (how can we make ICT itself more sustainable?) and Green by IT (how can we achieve sustainability through ICT?). On a closer look, it is software that links these two fields: In “classic” Green IT, there are many ways to build and use hardware in a more energy-efficient way. On the software side, Green by IT has often been software-based until now, involving tools that help to optimize logistics and automate processes to save energy, for example. However, the debate over software-induced energy consumption is just beginning. To date, few studies have been conducted about the energy saving potential of software itself. Therefore, it is important to investigate the meaning of sustainable software and sustainable software engineering. This chapter provides definitions of these concepts. In addition, it presents a reference model of sustainable software as well as its engineering. However, it provides only a short introduction of the model itself. The sub-model “Sustainability Criteria for Software Products” and sustainable software process models are examined in greater detail.

Green Software and Green IT: An End Users Perspective

Caused by the movement to a sustainable development, Green IT is still a big trend and more than just a buzz phrase. Especially data centers are working on their own energy efficiency. Additionally, Green IT needs to involve end users as the ones who play a decisive role in the utilization phase of ICT (ICT: information and communication technology) devices as well as software products according to the idea of Life Cycle Thinking. In our chapter, we describe some typical end user software usage scenarios and take measurements to ascertain the energy consumption induced by these. We compare the energy consumption of word processors as well as the energy consumption induced by web browsers. In regard to sustainable development, the user has to be involved in the movements of Green IT.

Sustainable software products—Towards assessment criteria for resource and energy efficiency

Many authors have proposed criteria to assess the “environmental friendliness” or “sustainability” of software products. However, a causal model that links observable properties of a software product to conditions of it being green or (more general) sustainable is still missing. Such a causal model is necessary because software products are intangible goods and, as such, only have indirect effects on the physical world. In particular, software products are not subject to any wear and tear, they can be copied without great effort, and generate no waste or emissions when being disposed of. Viewed in isolation, software seems to be a perfectly sustainable type of product. In real life, however, software products with the same or similar functionality can differ substantially in the burden they place on natural resources, especially if the sequence of released versions and resulting hardware obsolescence is taken into account. In this article, we present a model describing the causal chains from software products to their impacts on natural resources, including energy sources, from a life-cycle perspective. We focus on (i) the demands of software for hardware capacities (local, remote, and in the connecting network) and the resulting hardware energy demand, (ii) the expectations of users regarding such demands and how these affect hardware operating life, and (iii) the autonomy of users in managing their software use with regard to resource efficiency. We propose a hierarchical set of criteria and indicators to assess these impacts. We demonstrate the application of this set of criteria, including the definition of standard usage scenarios for chosen categories of software products. We further discuss the practicability of this type of assessment, its acceptability for several stakeholders and potential consequences for the eco-labeling of software products and sustainable software design.

Including Software Aspects in Green IT: How to Create Awareness for Green Software Issues

While counteracting the increasing demand for natural resources and especially energy of ICT, first successes have become apparent by activities comprised by the term “Green IT”. Nowadays, many of the current activities lay emphasis on the hardware side of Green IT. However, software issues play a significant role in defining system and hardware requirements as well as the amount of energy consumed by ICT devices and the underlying infrastructure. Thus, the following chapter introduces the idea of green software and its engineering. Complementary to definitions and models in the addressed field, a more practical insight is given by illustrating exemplary energy measurements of software products. While these aspects show that the research is increasingly dealing with software issues of Green IT, these mainly scientific ideas have hardly reached practical relevance, so far. Hence, following the life cycle perspective of software products, we present two exemplary concepts on how to increase awareness of green software: addressing especially software engineers, we propose to implement continuous energy efficiency measurements during the development phase. With regards to software users, we propose to create an eco-label for software products to inform about their environmental issues and thus create more transparency in this context. To do so, we present and evaluate criteria and indicators, upon which a label could be based. The chapter concludes with a summary and proposes future activities in the addressed field. Overall, the aim of the chapter is to point out solutions that might lead to a more environmentally friendly way of developing software, a well-informed procurement behavior regarding software products, and a more sustainable user behavior concerning ICT.

Bewertung der Nachhaltigkeit von Software: Entwicklung einer Umweltkennzeichnung

In diesem Beitrag werden Ansatze zur Entwicklung eines Labels fur grune und nachhaltige Software vorgestellt. Wahrend fur den Bereich der Hardware bereits zahlreiche Labels wie ENERGY STAR, TCO oder auch Produktkategorien des „Blauen Engel“ existieren, liegen fur den Softwarebereich bisher erst einzelne Kriterien und Untersuchungsergebnisse vor, die aber noch nicht zu einem veroffentlichten Label zusammengefasst sind. Basierend auf den Kriterien fur Hardware sowie einer Umfrage werden daher Uberlegungen entwickelt und uberpruft, welche den Bereich der Nachhaltigkeit von Software in den Fokus nehmen. Da umweltbezogene Kennzeichnungen auch im betrieblichen Kontext eine wichtige Rolle zur Erreichung von Nachhaltigkeitszielen spielen, sehen wir durch diese Kriterienentwicklung einen Beitrag zur Verbesserung der Ressourceneffizienz von IKT, der sich auch auf die Anwendungsdomanen von Software ubertragen lasst. Eine von uns durchgefuhrte Umfrage bestatigt diese Bedarfe insbesondere hinsichtlich Energie- und Hardwareeffizienz.

Supporting Sustainable Development in Rural Areas by Encouraging Local Cooperation and Neighborhood Effects Using ICT

The following contribution presents an approach how information and communication technology (ICT) can be used to support local cooperation and neighborhood effects. The presented approach maps typical real-world processes in the area of local cooperation between stakeholders from schools, universities, and companies to an Internet platform with the motivation to support the communication between the aforementioned audiences and thereby reduces demographic problems in the model area in a sustainable, long-time perspective. The contribution describes the process from the conceptual application of the idea as well as the prototypical realization of the technical prototype vitaminBIR. This encompasses, from the conceptual perspective, the definition of the main goals of the platform supported by a survey collecting needs and preferences of all addressed audiences and the conceptual phase of the platform itself. Furthermore, from the implementation perspective, the prototypical implementation is supported by different software libraries, a concept for data self-management, and an iterative usability study to also check against the prior evaluated needs and preferences of the audiences, is addressed. A first usage analysis is presented at last.

Processes for Green and Sustainable Software Engineering

Within research in the context of ‘Green (in) IT’ (ways to make ICT itself greener) and ‘Green by IT’ (possibilities to encourage environmental-friendly movements by ICT), it turned out that, next to the hardware aspects, the software side also gains big importance. Software causes hardware activity and is responsible for energy consumption in that way. It became an important aspect of the daily life, and most people cannot imagine future development without software.