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.