# A Soft Computing Framework to Support Consumers in Obtaining Sustainable Appliances from the Market
## 1 Introduction  
According to [1; 2; 3; 4], the consumption of energy should be reduced in order to achieve sustainability. Approximately 38% of the final energy consumption is related to the building sector, and from that percentage, approximately 18% is related to the residential sector [4], which thereby represents a relevant sector for which to achieve sustainability. With regard to household appliances, some measures have been made not only in Europe but in other world regions as well, in order to promote sustainability in this sector. One of such measures, adopted in this context, is mandatory labeling [5; 6; 7; 8], which allows informing the consumers about information related to each electrical appliance, such as heat capacity (air conditioner), water and energy consumption (dryer machine), and initial investment (lighting), among others. The goal of such a measure is to adjust each available solution to the consumer's needs [6; 7; 8]. Besides energy labeling, there are also eco-design policies, with both acting as essential tools to drive the shift from a \"linear economy\" to a more \"circular\" one that also promotes sustainable development [9; 10]. Furthermore, and by including eco-design and energy labeling measures, the European Union has changed the way that our products are designed, bringing substantial reductions in terms of greenhouse gas (GHG) emissions and the corresponding consumption costs [4; 5]. By 2020, and based on [9], the European Commission estimates that the energy consumption costs for each household in Europe will be approximately reduced by \(\xi\)300 per year, due to the adoption of such policies, with GHG emissions also seeing a reduction of approximately 319 megatons of CO\({}_{2}\) (equivalent) per year. According to some studies, which include the EU's recommendations, increasing the durability, reparability, and recyclability of the products and, in particular, electrical appliances, represents an opportunity to improve eco-design and energy labeling measures with respect to the promotion of a circular economy [3; 4; 5; 6]. Although sustainability is a goal to be achieved, the circular economy is a way to achieve such an end, therefore being a road map that should lead society to reach sustainability [4]. However, some studies argue that the circular economy will not be enough to achieve sustainability [4; 8], since it only focuses on technological progress to solve economic and environmental problems, making it a \"weaker\" sustainability approach [9; 10]. On the other hand, the rise of new developments resulting from the combination of information technologies with decision support systems, together with new business models of product service systems as well, could also help to satisfy the need for cultural change in order to reach a \"stronger\" sustainability approach [5; 8; 9]. The circular economy is a means to achieve sustainability since it helps (directly and indirectly) meeting targets of the Sustainable Development Goals defined by the United Nations [11]. As mentioned before, energy labeling policies, as well as eco-design, are essential tools to drive the shift to a circular economy [12]. Several studies regarding the circular economy and sustainable development issues have been developed by considering several contexts (e.g., market surveillance of resource efficiency [9], energy renewables [13], circular economy performance indicators [12; 13]). In recent years, several entities, including governments, associations, and manufactures, have also used measures in an attempt to sensitize the population to the problem of energy efficiency in the residential sector [14; 15; 16]. Despite the existence of such measures, it becomes difficult for a decision-agent (consumer) to acquire the best solution adjusted to its needs and preferences, given the diversity of options from the market (brands and models) as well as the diversity of the appliance's own features [14; 15; 16].