**5. Discussion**

This paper began with a brief history of computing and the data centre industry, outlining established thought process and practice in the general engineering profession and data centre industry. This review was necessary in order to contextualise the scale and nature of the current and future challenges facing the sector unless there is a significant change from a linear to circular economy. The paper then describes two methods (Design Thinking and the Double Diamond Framework for Innovation), which underpinned CEDaCI, a unique project that was set up to kick start the Circular Economy for the Data Centre Industry. People and stakeholder engagement are central and critical to the design methods; however, the DCI is very fragmented and silo working is the established practice in the various sub-sectors so there was a risk that the project would be compromised, or fail to deliver, because of lack of engagement. The project team used various strategies to engage stakeholders; this has proved successful so far, and the CEDaCI team has built a Network with 100 members. All Working Groups meetings and Co-creation Workshops are also well-attended, and participants appear to fully engage with the project team and each other throughout.

In order to assess the impact of the project, the level of stakeholder engagement and the success of the design methods, quantitative and qualitative data were collected and analysed via an on-line survey and semi structured interviews. The overall response from this research indicates that the project is very well received and is fulfilling aims so far; the enormous scope of the project means that creating a sectoral circular economy in three and a half years is unrealistic but the project is raising awareness across the sector and demonstrating that a CE is possible. For example, participant (D) volunteered that "*CEDaCI has created an awareness and an interest to look into the topic of the circular economy. That's a huge success. That will create a big change on the market*".

The participants' response to the WG meetings and CCWs has exceeded expectations; the aim of these events to was to bring together actors from across the DCI to enable whole systems approach, to address the challenge of a sectoral Circular Economy, by encouraging knowledge transfer and exchange, and the following comments from participants indicate that this objective is being realised: for example, (F) commented that "*You must be achieving (the Circular Economy) to some extent because there has been awareness raising. You have brought together stakeholders from around the value chain. They have knowledge that no others do*." And "*I've met some interesting people that I've been able to bounce ideas off of. Some of the experts bring insight and knowledge that I couldn't get from the papers*" and (G) said that "*the biggest benefit is meeting other people with other perspectives. The community aspect is one of the benefits of working groups*". Stakeholder engagement is proving mutually beneficial and the CEDaCI team are continually learning from the industry partners; what is learned is feeding into the Pilot projects, and other output, to ensure that it both meets DCI requirements and initiates change towards a circular economy.

Although the feedback from the two research exercises is all very positive, it must be remembered that the research has limitations: the participants are already committed to sustainability and sustainable development, and they all work for organisations that are either promoting and/or practicing it. A bigger challenge is engaging and educating stakeholders who are not interested, are still totally focussed on energy efficiency (rather than that and physical resources), or believe that any products that are sent for recycling are actually recycled rather than being stockpiled, sent to a landfill, or that second life products cannot possibly meet their requirements.

These stakeholders may be forced to change practice in order to conform to any new and future legislation, although the CEDaCI project will publicise incentives such as the CDCC tool, models, and case studies to illustrate the economic, and other, benefits of adopting circular practices.

Despite these short comings, the research shows that project is leading change, which validates the use of design methods; the project is also an exemplar, and the methods and underlying structure can also be transferred to other sectors to support their transformation to circularity.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/su13116319/s1, The supplementary materials comprise questions for qualitative and quantitative data collection via the on-line survey and the semi-structured interviews.

**Author Contributions:** Conceptualization, D.A., N.A., J.C. and K.B.; methodology, D.A, N.A., J.C. and K.B.; software, E.J.N.; validation, D.A.; E.J.N.; formal analysis, D.A. and E.J.N.; investigation, D.A., N.A., J.C. and K.B.; resources, E.J.N.; data curation, E.J.N.; writing—original draft preparation, D.A.; writing—review and editing, D.A. and E.J.N.; funding acquisition, D.A. and N.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by ERDF/INTERREG NORTH WEST EUROPE, grant number 787.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Ethics Committee of LONDON SOUTH BANK UNIVERSITY (protocol code SoE28012021; approval confirmed by Chair of Ethics via email on 28 January 2021).

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Anonymised data can be obtained by contacting the lead author.

**Conflicts of Interest:** The authors declare no conflict of interest.
