## 4 Literature Review Outcomes
### Presentation of the Perspectives Outcomes  
In this section, the outcomes of the SLR are presented based on the investigated papers and summarized by graphical representations. Moreover, they are assigned to each analyzed perspective. 1. Supply chain processes. Based on the results of the content analysis, Figure 5 shows that the majority of the previous papers study the effects of digital technologies on SCs as an overall process [68; 69; 70]. In fact, there are few papers that investigate the impacts of each individual technology on specific SC processes. However, IoT appears to be more investigated than the other technologies in relation to Lean principles application in different processes such as Warehousing, Manufacturing, and Inventory Management. Additionally, there are a few papers studying the BDA effects on Lean warehousing. On the contrary, there is no evidence about adopting AM and CC in single processes in Lean DSC, although, they were investigated to address the overall SC. 2. Supply chain-associated issues. According to the results depicted in Figure 6, a considerable part of the investigated papers studies the impacts of Lean and digital technologies on information sharing as a key operational SC issue. However, a vast amount of papers still does not discover the effects of Lean DSC on the other SC issues in order to devise solutions to increase SC efficiency. For example, scheduling, risk management/assessment, and revenue/cost-sharing. Nevertheless, there are few efforts to improve sustainability by combining Lean principles and digital technologies. In this regard, CC, BDA, AM, and Industry 4.0 as a general concept  
Figure 5: Distribution of papers: SC processes. are applied to enhance the main pillars of sustainability. However, for each single technology researchers just referenced the environmental effects and they did not address the impact of each single technology on the other three bottom lines such as economic and social issues. Moreover, a noticeable number of papers evaluate the effects of Lean DSC on performance assessment/measurement but the investigated digital technologies are limited to CC, BDA, IoT, and also these works mostly refer to Industry 4.0 in general. (c)Supply chain-applied methodologies. Various methodologies are currently applied to address the Lean DSC (Figure 7). To this end, the survey/case study category reveals as the dominant one for investigating CC, BDA, IoT, and Industry 4.0 in general, applied together with Lean principles. Additionally, it should be noted that, except for the work by [71] on AM, there is no paper applying the literature reviews to discuss single digital technologies in relation to Lean Manufacturing. Besides, conceptual framework proves to be a popular methodology, applied for debating CC, IoT, and Industry 4.0 in general. Additionally, hypothesis testing is considerably used but not adopted to study all the single digital technologies except for CC, and BDA. Surprisingly, less attention is paid to the application of simulation to Lean DSC. Nonetheless, this is a promising methodology to illustrate the possible impacts of the application of Lean DSC in different conditions to assist practitioners in developing appropriate implementation roadmaps. Figure 6: Distribution of papers: SC-associated issues. 4. Combination of digital technologies in SCM. Figure 8 depicts a comprehensive picture of the combination of different digital technologies in Industry 4.0. All of the identified digital technologies at the end of step 1 in Section 3.1.3 are considered to figure out the power of each pair for concurrent application. The thickness of lines among each pair of digital technologies in Figure 8 indicates the strengthening of that relationship, calculated by dividing the number of papers considering the joint implementation of the two technologies by the total number of investigated works (64 papers). CC shows the most powerful relationships with BDA (22%), IoT (20%), and AM (19%).