2.1. STS—Sociotechnical System
There are multiple bodies of literature contributing to STSs. The various theories each have a different focus on what predominantly determines the evolution of an STS. Historically, research on STSs originates from the question of how the work environment affects human performance, such as in coal mines [
18]. According to Hughes [
19], elements of an STS can be categorised into physical artefacts, organisations, scientific research, legislative artefacts, and natural resources. In general, much research on STSs focusses on the relationship between society and technology. Similarly, in the theory of large technical systems, the relationship between actors and technology determines how systems develop over time. The actor–network theory sees that actors are more important in determining the development of STSs [
20], whereas transition theory sees that STSs are determined through societal regimes [
7].
Geels [
21] defines STS “as the linkages between elements necessary to fulfil societal functions” (p. 900). Transformations of STSs are dynamic processes that occur on three levels: the niche, the regime and the landscape level. On the niche level radical innovations emerge, the regime level includes the set of rules represented by institutions that structure the STSs, and the landscape level comprises exogenous long-term aspects such as demographic trends, or climate change [
22]. Within this three level-concept, design thinking seems to have potential to contribute to the niche and the regime level. This perspective suggests that society and technology co-evolve. It entails a broad research scope where STSs serve as a unit of analysis. In this line of research, there is also consensus that a main challenge is to understand how the STS components interact and how system change affects sustainability [
23]: also, there is a common understanding that system complexity stems from feedback loops, self-organisation, and system hierarchies [
23]. STS changes are a function of the interactions between technology, economy, institutions, human behaviour, as well as culture [
23]. Burk [
24] argues that STSs are the result of power struggles, and the interest group with the greater political power will be most impactful on shaping an STS.
The multi-level perspective is suitable to investigate societal systems such as urban transportation [
7] or domestic heating [
20], and how its components are interlinked. When thoroughly investigating, for example, the resource use of a product to obtain effective and efficient interventions, it is necessary to look at the product, the related services, consumer usage, material sourcing, production, and end-of-life operations in an STS. Advanced analyses may even compare various business model configurations and or policy changes when taking a long-term perspective.
We employ the STS as a unit of analysis for design fixation on the institutional level as described below. We narrow our scope to system components that are most relevant for the estimation of the environmental impact of specific consumer behaviour, such as lifecycle aspects of products and services, population dynamics or consumer behaviour.
2.2. Design Thinking and Its Application to Sustainability
Design thinking applies the principles of design to a broad set of challenges [
25]. Finding creative ways of solving problems is an important part of it, as well as integrative and holistic types of thinking. Two famous examples of great design thinking are Thomas Edison’s light bulb and Apple’s iPod. Both examples are not just about a product but an entire eco-system around the product that makes it much more enjoyable [
15]. Design thinking is about finding out the real needs and capabilities of people, also known as human-centred design. Typically, it is necessary to step back from a given problem and try to understand the real issues first. Design thinking first seeks to understand the problem and then finds a solution at a later stage [
26]. Prototyping and participation with problem owners and divergent thinking are also key notions of design thinking. Thereby, design thinking is apt to solve so-called “wicked” problems. Some principles of design thinking, such as experimentation, [
27] have been reported to be part of many developments and designs of sustainability-related STSs [
27,
28] or in urban environments [
29].
The ideal design thinking process is often described as an iterative process with multiple steps. The Stanford way of design thinking is framed into five stages: emphasise, define, ideate, prototype and test [
30]. Norman uses similar terms, namely, observation, ideation, prototyping and testing [
26]. A different way of seeing the design process is dividing it into two phases—finding the right problem and finding the right solution (the Double Diamond model of design). Yet another way to define the phases of design thinking comes from Brown and colleagues, who talk of the three innovation spaces of inspiration, ideation and implementation [
25]. In the first stage, the designer needs to understand the problem at hand. The real underlying problem can be different from the apparent problem, and the designer needs to be quite certain that she/he understands the real problem. This step requires gathering data from the problem owners and an in-depth knowledge of the problem. Next, the second phase is about finding the patterns that are causing the problem, while the third phase requires formulating design principles that help to incur the right kind of behaviour among the target group. In the fourth step comes the prototyping phase, where something tangible is embodying possible solutions. Finally, the fifth phase is about testing and potentially starting a new iteration of the whole process [
30].
As an example of research applying design thinking to a real-world challenge, Cole, et al. [
31] discuss design thinking in the subject of the built environment and argue that the benefits of design thinking include a stronger theoretical framing by expanding the scope in the space dimension, that is, widening the boundary focus of a building from its site to the neighbourhood [
31]. This framing is expected to help identify opportunities for synergistic interactions with other elements beyond the design object at hand. The hallmark of design thinking is that it brings in an expanded view to problem solving and points at several intervention points that could be missed otherwise. Similar thinking evoked through the systems perspective has been highlighted in literature such as industrial ecology [
32] or industrial symbiosis [
33].
Previous works have applied design thinking to the sustainability challenge. Clune and Lockrey [
34] use a mixed approach. First, they applied an LCA to understand the areas where the underlying system of an elderly care centre caused the highest environmental impacts (i.e., the first diamond of finding the problem). In a second step, they found alternative practices through creative design thinking methods that supposedly helped to substantially mitigate the environmental impact in terms of the reduction of carbon emissions over a ten-year time frame (i.e., the second diamond of finding the solution). The result was a mix of new social practices and technical (e.g., energy usage) and organisational (e.g., procurement processes and planning) measures that alleviated the environmental impact from multiple angles [
34]. This approach is an example where a wider perspective, in this case, an organisational perspective, was used to design an intervention that improved the environmental performance to a much larger degree than a purely technological solution could have done. A similar direction has been taken by Kanda, Sakao and Hjelm [
8] who looked at environmental benefits that emerge when applying a large technical systems perspective. Geissdoerfer, Bocken and Hultink [
6] adopt design thinking to enhance an existing sustainable business model innovation process by supporting the creation of additional value and including more stakeholders of relevance. Bocken et al. (2019) apply user-centeredness, participation, and experimentation to find creative ways to make business models more sustainable.
Shapira, et al. [
35] point out that while design thinking was very useful in fostering creativity and holistic solutions, it does not inherently support sustainability. The authors suggest a “sustainable design thinking process” which particularly included steps focussing on sustainability issues. Their method was presented in a generic form and broadened the design thinking perspective from mainly human-centred to a long-term and systems perspective [
35].
What the above-mentioned examples all have in common is they extended their scope in order to find superior solutions with a lower environmental impact. Yet, even though the existing research applies design thinking for the sustainability challenge, little research has been found that aims to identify opportunities for better design on an STS level.
2.3. Design Fixation
Design fixation is an established concept in engineering design (see origins in [
13]). Famous examples come from descriptions of large companies like Rolls-Royce and Sony, where design fixations lead to substantial delays in the product development of turbines or the CD players, respectively [
36]. Design fixation is a critical barrier in the ideation stage for creating potential concepts towards design solutions, and thus it is to be avoided in implementing design thinking, where creativity is highly embraced. A classification of design fixations is available [
15]: unconscious adherence, conscious blocking, and intentional resistance.
Unconscious adherence is, for instance, a phenomenon where designers commit to the concepts that they think of first without realising other concepts [
37]. Conscious blocking, which also corresponds to the so-called “curse of experience” [
15] or cognitive entrenchment [
38] in other disciplines, may occur where experience leads to the development of decision rules, heuristics, etc. This may allow for quicker solution finding but at the same time may lead to a problem framing from this body of knowledge and may hamper the generation of new ideas [
15,
38]. Intentional resistance is a kind of nostalgia where previously successful designs are favoured over new ones, which may also be risk-averse behaviour [
15]. This arises from a certain short-term bias where new developments or investments are not given enough time and are discarded before they can evolve. Historical examples may be the non-adoption of the metric system in America or holding on to outdated technologies [
15].
The other categorisation of design fixation is conceptual versus knowledge-based fixation; the former refers to the situation where a single design concept is considered for a solution, while the latter refers to where knowledge only within one area is used [
15].
Design fixations may occur for different reasons. In planned obsolescence [
39], product developers deliberately choose shorter-life components to maintain or increase the income from selling products, which may be classified into conscious blocking. Further, concerning knowledge on requirements, engineering designers tend to focus on technically specified requirements [
40]. This may also lead to unaccepted products due to their failure to consider unspoken customer needs that are widespread in marketing, which in turn may correspond to knowledge-based fixation with unconscious adherence.
Methods for preventing the various types of design fixations were summarised in a literature review [
15]. A timely warning to consider all options is suggested for unconscious conceptual fixation [
41], and including physical prototyping materials during the conceptual design to inform of phenomena in different domains is a possible remedy for unconscious knowledge fixation [
15]. For conscious blocking, short breaks are considered useful [
42]; also, design training methods, for example TRIZ [
43], are possibly effective, and computer-assisted design is beneficial [
44]. Intentional resistance is left with no known conceivable remedy but interdisciplinary cooperation, creativity exercises, or changes in beliefs [
45]. Regarding practice in industry, based on interviews with expert designers, Crilly [
46] categorised practices into five factors that discourage fixation: teamwork with other designers, systematic design methods, facilitation by experts, making of computational or physical models and expectations by clients.
As briefly reviewed above, design fixation was mostly analysed at the micro level of design and mainly in an industrial or manufacturing context, i.e., focusing on the activities of an individual designer or a group of designers in one manufacturing organisation. Considering the importance of the systems perspective and the STS, applying the concept of design fixation and its associated knowledge to the higher levels is expected to create useful insights in the sustainability context.