Keywords

1 Introduction

Genovese et al. [13] distinguish between a green and sustainable supply chain (SC) and the economy circular (CE) concept. A green SC refers to the strategy of integrating environmental issues into manufacturing organisations by reducing material flows or minimising the negative consequences of production processes [31], i.e. a linear SC. The CE concept is related to production methods that are self-sustaining and true to nature, where materials are used over and over again [26]. Here Geissdoerfer et al. [12] consider sustainable development to be a broader and more intangible concept than CE, which could be converted into a more tangible way to organise the society and economy, and to define circular SC management as the configuration and coordination of organisational marketing tasks, sales, R&D, production, logistics, IT, finances and customer services within and between business units and organisations to minimise the system’s input resources and loss of waste and emissions, improve its operational effectiveness and efficiency and create competitive advantages.

Simultaneously, digital technologies enable SC management in the current Industry 4.0 (I4.0) context to evolve [18]. In this context, Nascimento et al. [28] focused on sustainable SC management, additive manufacturing and smart production systems to address how I4.0 technologies can be integrated with CE practices. Daú et al. [9] simultaneously define sustainable SC and 4.0 as that which uses I4.0 tools to close materials and energy cycles and to help information and activities to flow. Manavalan and Jayakrishna [24] recommend using I4.0-related technology in the transition from a linear to a circular SC.

We herein present a summary of a more general review on SC 4.0 and on CE reviews, conceptual and analytical approaches. This review aims to act as a starting point for novel optimisation and simulation models for SC 4.0 according to CE criteria.

2 Review Methodology

The review methodology was based on exploring articles by employing mostly the Scopus scientific and technical database and the Web of Science to a lesser extent. No time restrictions were set. Articles were searched for and observed by combining several keywords, which were later selected in line with the selection criterion of these keywords. We now summarise the number of articles selected by searches based on these keywords: supply chain, circular economy, Industry 4.0: four results; supply chain, Industry 4.0: 13 results; supply chain, circular economy: 13 results; optimisation, supply chain, circular economy: two results; supply, chain, circular, economy: seven results; and Industry 4.0, supply chain, green, circular economy: one result with a total of 40 results.

The scientific sources of the selected articles are recognised in the research area. Table 4.1 presents the scientific sources from which 24 articles were taken.

Table 4.1 Scientific source and selected references
Full size table

3 Literature Review

We classify the reviewed works in terms of objectives and context, research methodology, benefits and limitations.

3.1 Objectives and the Application Context

Table 4.2 summarises the objectives and the application context of the reviewed papers.

Table 4.2 Objectives and application context
Full size table

Regarding the main objectives of the reviewed works, it is important to highlight the aim to integrate economic and environmental objectives into SC management [36]. Indeed the economic SCOR SC management model has been adopted to extend it towards circular SC practices [32]. Sustainability principles in SCs have also been addressed with optimisation models [27]. SC configurations according to sustainable [20] and circular principles have been analysed by several works [25, 30, 35], whereas the necessity for cooperation practices from consumers to suppliers has been studied [41, 42]. The government regulation to implement CE practices has been addressed [40, 42]. Several performance measurement systems or indicators have been proposed to evaluate circular SCs [16] to, for instance, compare linear and circular SC models [9, 12, 15, 24, 29].

On more ecological issues, direct, indirect and total life cycle emissions, waste recovered [17], virgin resources use, gas emissions [14] and carbon maps have been addressed by several works with circular principles [5, 13]. Finally, I4.0 technologies, such as IoT [4], optimisation algorithms, big data [34] and RFID [23], among others, have been applied to support digital SCs [2, 7, 18, 19, 33], logistics 4.0 [3, 37], sustainable SC management [1, 11, 22] and circular principles [10, 28, 38, 39].

According to the contexts to which the analysed papers apply, some works focus on automotive [5, 36], chemical and petrochemical, construction [7, 14, 29], electronic, food [13, 20], footwear and apparel [23], health care and mechanical, mobile [2], pharmaceutical [11] and steel [30] SCs. SCs, and global SCs in general, are also widely considered by several works [3, 18, 19, 32]. The interest shown in studies on I4.0 and logistics 4.0 has recently increased. Finally, it is important to highlight that the SC nationalities where case studies are conducted are basically Brazilian [9], Chinese [39,40,41,42,43,], European [30], Indian [7, 22, 24] with electronic and food [13, 20, 38] and Italian [17] and South African [1].

3.2 Research Methodology and Methods

According to Dangayach and Desmukh [8], the research methodologies classification of the reviewed works is as follows: (1) conceptual, basic or fundamental concepts; (2) descriptive, an explanation or description of the process or content and performance measurement issues; (3) empirical, study data from existing databases, literature reviews, case studies and taxonomy or typology approaches; (4) exploratory cross-sectional by surveying at one time point; (5) exploratory longitudinal, where data collection was done at two time points or more. Table 4.3 summarises the research methodology followed in the reviewed works.

Table 4.3 Research methodology (RM) and methods
Full size table

Here conceptual approaches are based mainly on systematic literature reviews. Descriptive methodologies generally propose frameworks validated through performance measure systems or indicators. Empirical approaches address case studies and practical examples. In this empirical methodology, the LCA methodology has been applied by several works. Finally, it is worth highlighting that analytical approaches and real-world applications scarcely appear in the reviewed papers.

3.3 Benefits

Table 4.4 presents the main benefits identified throughout the reviewed papers.

Table 4.4 Benefits
Full size table

3.4 Limitations and Critical Points

Table 4.5 summarises the main limitations and critical points identified throughout this review.

Table 4.5 Limitations and critical points
Full size table

4 Discussion and Conclusions

The CE concept promotes continuous economic development without implying significant environmental and resources challenges. This is supported so that economic systems can, and must, operate according to the principles of the materials and energy cycles that sustain natural systems by emphasising the capacity of an organisation’s waste being used as another organisation’s resource via self-organisation capacity [41, 42]. Thus, one of the main challenges of implementing CE initiatives is to pay attention to economic implications [13]. So finding ways to align sustainable SC strategies with CE principles and understanding all the economic–environmental implications to do so are most important if we wish to broaden the limits of environmental sustainability, especially in intensive energy and materials industries [29]. In other domains for example, the main problems that prevent sustainability involve high costs and long times, little experience and training, the application of regulations, few commercial incentives, inefficient collaboration and coordination, lack of objective target reference points and barely any knowledge about end customers [11]. Govindan and Hasanagic [15] are in favour of promoting CE by a governmental perspective, i.e. laws, policies, risk reduction (through tax levies) and strict governance.

This CE paradigm will, in turn, be applied to an I4.0 context, specifically a logistics 4.0 context, which is understood as the combination of logistics with the innovations and applications of cyberphysical systems [3]. Industrial production systems must be balanced from the environmental, social, economic and technological points of view. Here it is important to highlight the work by Lopes de Sousa Jabbour et al. [21], who propose a first roadmap towards I4.0 and CE based on the ReSOLVE business model; or Dallasega et al. [7] distinguish different proximity dimensions: technological, organisational, geographical and cognitive. These findings demonstrate that not all I4.0 concepts affect all proximities to the same extent.

In short, this paper presents a preliminary literature review on research work oriented to SC 4.0 initiatives with CE principles. Here the objectives and application context and the research methodology of the reviewed works are analysed. An overview of the main benefits and limitations is addressed. This work identifies the need for more conceptual and empirical research to provide a framework and analytical models towards SC 4.0 with CE principles. Hence, optimisation and simulation models are required to support decision-making to optimise CE and I4.0 practices in SCs. Finally, the validation of these new optimisation and simulation circular SC 4.0 models should be validated with real-world applications.