The Life Cycle of Software Products

The Development Phase accounts for impacts on SD that directly result from activities in-volved in software development, as well as indirectly involved activities, e.g. proportional impacts of common corporate departments.

Environmental impacts to be considered in-clude, for example, electrical energy that is necessary to power the workstations of soft-ware developers and other employees, electrical energy and natural resources that are necessary to operate the IT infrastructure (e.g. networking devices, servers, and storages), energy that is necessary for heating and air conditioning, electrical energy that is necessary for offices lighting, or energy for transportation purposes like long distance business trips for meetings with customers and the development team, and even the employees’ daily way to work.
Social impacts can be working conditions and payment of offshore workers (e.g. developers, type setters), which have consequences for the workers and their families.

Some of these impacts can be mitigated by introducing teleworking and teleconferencing, or by replacing material products with ade-quate immaterial substitutes (second-order effects). This in turn may induce, e.g. changes in organizations, software development methods, or life styles (third-order effects).

The Distribution Phase accounts for impacts on SD that result from distributing the software product. This includes environmental impacts, e.g. of printed manuals (type of paper and ink), chosen means of transport, type and design of the retail and transport packaging (e.g. plastic, polyurethane foam, biodegradable material), or data medium (e.g. CD/DVD, USB memory stick). Furthermore, if the software product is offered as a download then its download size should be considered, as well as the electrical energy and material resources that are necessary to operate the required IT infrastructure.

The Disposal Phase accounts for impacts on SD that result from disposal and recycling of the afore mentioned material sub products.

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.

If a software product is taken out of service, it is mostly necessary to convert the available data to a format that can be processed by the succeeding software product, or to make it accessible in some other ways. If the data cannot be converted easily, e.g. because it is stored in a proprietary format, this may have an impact on economic sustainability of an organization.
In this phase, even the backup size of data matters, e.g. if legal regulations require long-term storage of data.

1. Berkhout, F., Hertin, J. (2001): Impacts of Information and Communication Technologies on Environmental Sustainability: speculations and evidence. Report to the OECD. http://www.oecd.org/dataoecd/4/6/1897156.pdf [2011-03-02]
2. Göhring, W. (2004): The Memorandum “Sustainable Information Society”. In: Minier, P., Susini, A. (eds.): Sh@ring. proceedings of the 18th International Conference Informatics for Environmental Protection, EnviroInfo 2004, October 21-23, 2004, CERN, Geneva (Switzerland), Éditions du Tricorne, Genève, pages 278–286.
3. Hilty, L. M. (2008): Information technology and sustainability. Essays on the relationship between ICT and sustainable development, Books on Demand, Norderstedt.
4. Behrendt, S., Kahlenborn, W., Feil, M., Dereje, C., Raimund, B., Ruth, D., Michael, S. (2007): Rare Metals. Measures and concepts for the solution of the problem of conflict-aggravating raw material extraction - the example of coltan, Umweltbundesamt.