# A Review on the Lifecycle Strategies Enhancing Remanufacturing
## 2 Methodology  
In order to better outline the strategies that enhance remanufacturing, a systematic review was conducted. This systematic approach was used to enable the review process to be reproduced, which is a key quality when completing a review of this type [25].The area of investigation did not focus on a specific strategy but was aimed at sorting out the strategies, highlighting the role they play in enhancing remanufacturing and how they have evolved throughout the years. For this review paper, the collection of information was done in several stages with articles selected from databases using keywords. As recommended by [PERSON] et al. [26], the papers for our review were selected from Science Direct, Web of Science and Scopus, which have all been widely accepted by the likes of [27; 28]. This review was done with no filter applied to the publication year and study type so as to avoid bias [29]. To avoid missing important literature due to labeling of the same concept, search terms included \"circular economy\", \"reverse logistics\", \"closed-loop supply chain\", \"EoL product collection\", \"smart remanufacturing\" and \"pre-determined remanufacturing timing\" which were each matched with \"remanufacturing\". Figure 1 below summarizes the inclusion and exclusion criteria and the processing, cleansing and assessment of the literature. The inclusion of at least one key word in the body of the text was critical to its retention. The articles that contained \"remanufacturing\" but not the other keywords in the main body of the text were not automatically excluded. This is because certain articles talked about some lifecycle strategies but did not mention them in the keywords. However, articles that did not contain any of the keywords in the abstract and conclusion were excluded. Non-English articles, non-journal articles and conference articles were excluded. After using Endnote X8 to remove duplications, 512 potentially relevant articles were retrieved from between 1995 and May 2021. A total of 331 of the 512 articles were cleansed for coding in NVivo12 (a qualitative data analysis software) to provide a quantitative assessment of contribution based on the coverage of the database search keywords in addition to the strategies that enhance remanufacturing. The software was used to extract literature affiliated to the various keywords in the 512 selected articles. After full text reading and further screening was done, articles which did not stress any of the keywords were discarded. Finally, 181 relevant articles are retained for this review paper. Figure 2 below shows the distribution of the relevant papers over the past years. It can be observed that most of the relevant papers appeared after 2010. This is due to the fact that remanufacturing has been gaining more attention over the past ten years as a result of the strong need to attain absolute sustainability by 2050 [2]. It could also be due to the increase in the number of remanufacturing conferences held annually that attract the attention of researchers. As seen in the distribution, there was a gradual increase in the number of publications as the years go by. This is due to an increase in the awareness of remanufacturing as a key recovery option for end-of-life products. Figure 1: Literature review process. The relevant papers were quantified and coded based on which strategies they had an impact on, the lifecycle stage in which they were applied and the case studies used to demonstrate the theory. Table 1 below shows the case studies used for each strategy. A graph has been plotted to show the distribution of the strategies over the years from the relevant papers we identified (see Figure 3). From this graph we can identify which strategies were fading and which strategies were gaining more interest. It should be noted that certain strategies overlapped in some papers. It can be clearly observed that there was a constant increase in the number of publications containing each of the strategies every year.