Green Software and Green Software Engineering – Definitions, Measurements, and Quality Aspects

The two big fields of sustainability and Information and Communication Technology (ICT) are Green IT (how can we make ICT itself more sustainable) and Green by IT (how can we encourage sustainability by ICT). Taking a deeper look, software links these two areas: Regarding Green IT, there are a lot of solutions to build and use hardware in a more energy efficient way. But the debate how energy-intensive software might be is just beginning. In contrast, Green by IT is often software-based, e.g. by tools that help to optimize logistics and automate processes to save energy. But until now there are no considerations about the energy saving potential of software itself. Therefore, it is useful to take a closer look at what green software and green software engineering are. In our paper, we will describe a reference model for green and sustainable software, as well as its engineering and also give some definitions. Though, we will just give a short introduction of the model itself and, to distinguish our work from our previous research, zoom in on the sub model “Sustainability Criteria for Software Products”. Additionally, we describe a model to measure the energy efficiency of software and give an example of measuring results in our contribution. The next step is to clearly differentiate from other measurement models to position our approach within other efforts of software’s energy consumption.