UdZ 3-2012

37 Unternehmen der Zukunft 3/2012 UdZ solution during the life cycle. The life cycle assess- ment (LCA) methodology determines ecological impacts over the whole life cycle in a way that no negative external effects will be neglected, com- pare ISO 14040 (2006). Related to the LCA as- sessment there is a method called MIPS (Material Input per Service Unit). This method calculates all the natural resources used during the life cycle for a product or service related to a service unit, which has to be defined in each case. Overall five main categories of material inputs are considered in the MIPS method: biotic and abiotic resources, water and air consumption and movement of soil [5]. Beside other objectives, MIPS can provide indications of a sustainable life cycle and therefore will be used to measure the ecological impact of sustainable solutions during the development phase. There are no indicators or comparative values so far for sustainable solutions, so that the data bases are still need to be created. Measuring social impacts for sustainability is even more complex than measuring ecological impacts, as most of aspects of social sustainability are described in a qualitative way. Below some social topics are listed, recorded in the SA8000 guideline [6] defined by the non-governmental organisation “Social Accountability International” which must be considered by employers to create social acceptable workplace conditions: Child Labour, Forced and Compulsory Labour, Health and Safety, Freedom of Association & Right to Collective Bargaining, Discrimination, Disciplinary Practices, Working Hours, Remuneration, Management Systems. These criteria give a holistic view of different social aspects. Most of the criteria are taken for granted in many western countries like the prohibition of child labour. However further criteria like the criteria for discrimination are not yet established in all western companies, either. The SA8000 guideline displays a completed list of requirements and forms a very good guideline for companies and a well described basis which can be enhanced with further indicators helping to measure the current social sustainability (see figure 1, page 36). Modelling approach To handle these numbers of factors out of the three dimensions of sustainability and to evaluate their impact on the life cycle over time, a dynamic simulation model approach has been develo- ped. The methodology is based on the system dynamics approach which is predestined for this intention, because it enables the decodation of complex and dynamic systems over a chosen pe- riod of time and allows understanding a system’s behaviour with many causal relations [7; 8]. With this approach, businesses are able to forecast the impact on the life cycle during the development process also when factors and requirements of the solution change. For the utilization of the model some data concerning transportation, material, energy and labour consumptions/ demands must be collected and estimated. As a first step historical data was used as a starting point for estimation. Besides, scenario analyses helped to provide data of future developments (see figure 2). Conclusion and future steps The presented approach delivers a good starting point to make the impacts on sustainability fac- tors transparent during the development process. Companies can use the tool to compare their current solutions that they are about to develop, Figure 2: Schematic diagram from modelling approach FIR-Forschungsprojekte