The Usage Phase

The Usage Phase considers impacts that result from deploying, using, and maintaining the software product.

Here, maintaining means that administrators are in charge of installed software and support users in their organization. Thus, maintaining includes, e.g. the installation of software patches or updates, the configuration of software and computer systems, and the training of employees in regards to proper software usage.

Beside these effects, software usage has several first-order effects regarding environmental sustainability: In order to deliver its offered services, a computer program requires processing time, which in turn consumes electric energy. This may also require the consumption of services offered by other servers (consider e.g. Data Base Management Systems, Enterprise Resource Planning systems, or simply the WWW service), which causes additional power consumption.

State-of-the-art software systems usually require up-to-date and more powerful hardware than older software systems or previous versions. As a result, this causes hardware replacements in organizations as well as at home, when a new software product is introduced.

On the one hand, new hardware is typically more power efficient than older hardware, but on the other hand it has to be taken into account that the production of the new hardware and the disposal of the old hardware causes vast amounts of resource and energy consumption [3].

Mining the necessary ores, e.g. in developing countries, where social and environmental standards are very low, leads to considerable social and environmental impacts, which sometimes even culminate in armed conflicts [4]. There are also reports about old and even non-functional hardware that is exported from industrial countries to developing countries, where it is reused but more often recycled under doubtful circumstances in so called backyard facilities or just deposited on waste disposal sites, causing damage to the environment and people’s health[3].

The second- and third-order effects on SD that result from the usage phase, depend on the purpose of the software product. Some software products directly promote sustainability aspects, like resource or energy efficiency, because it is their intended purpose: software that enables smart heating, smart lighting, smart logistics, paper free offices, teleconferencing, etc. In these cases second-order effects can be easily assessed. However, there is also multipurpose software, like word processors, spread sheets, or graphics software. For these, it is nearly impossible to assess second- or third-order impacts, because software manufacturers usually do not know for which purposes their software product is used.

Finally, in order to avoid rebound effects, newer (and even more resource-efficient) versions and updates of software should be developed in such a way, that they do not enforce the procurement of newer hardware.