1. Introduction
In an interconnected world, enterprises and supply chains are continuously challenged by risks, uncertainties and market vulnerabilities [
1,
2]. The frequency of disruption is high, leading to a wide range of consequences, including human and financial losses. Disruption can take various forms, from the operational level to the strategic, including delays, quality obstacles in the production process, accidents or equipment failure, as well as pandemics and natural hazards [
3,
4,
5]. In this increasingly competitive era, with unpredictable events, fierce competition and high levels of market instability, organizations must invest resources to survive and sustain themselves. Consequently, organizations are seeking more reliable strategies for risk management of their supply chain to consistently and efficiently manage internal and external disruptions [
6]. According to Ivanov and Dolgui [
7], the prerequisite to effectively managing risk is to adopt a resilience paradigm in supply chain processes. Resilience can be considered as a proactive capability of any operating system to contend with minor or major disruptions [
8]. Resilience combines two essential components: the ability to reduce the destruction triggered by a particular risk and the capability to return to an acceptable level of performance under the effect of such risk [
9,
10]. The contemporary worldwide market has forced manufacturing organizations to pursue excellence in operational processes and enhance their performance to lower their costs and provide higher quality products in shorter lead times. Many scholars have investigated the role of resilience paradigms in supply chain. For example, Namdar et al. [
11] scrutinized the use of sourcing strategies to accomplish supply chain resilience under disruptions. Borekci et al. [
12] investigated the resilience of triadic buyer–supplier–supplier relations. Recently, Ivanov and Dolgui [
13] measured the resilience of organization under COVID-19 disruption in the supply network.
The “lean” paradigm has been used by manufacturing organizations to reduce costs and achieve a competitive advantage in the marketplace [
14]. The lean paradigm focuses on reducing waste [
15] to increase value-adding, fulfil customer needs and maintain profitability [
16]. Implementing lean principles has led to sustainable benefits for companies [
17], including an improved operational performance by reducing lead times and inventory and improved quality and productivity [
18,
19]. Lean thinking contributes to sustainability in multiple ways [
20,
21]. For example, Henao et al. [
22] investigated the literature around the integration of lean and sustainability performance, concluding that two are tightly interconnected across three themes—environmental, social and economic—and share similar goals and synergies. Despite this, lean principles lack the capability to respond to higher levels of volatility in the marketplace. To manage these challenges, companies must now consider both the lean and resilience paradigms together to achieve operational excellence. With the rapid development of knowledge in this complex area, there is a growing need to understand its context, framing and conditions. In response, this paper proposes a systematic literature review to analyze and understand the relationship between lean and resilience paradigms. It also investigates discrepancies and gaps in the literature and identifies new research directions required to address them. The study systematically collects and examines the current contributions on lean, relevant to its application to, and association with the resilience paradigm. Two research questions were adopted for this study:
What themes have been researched previously on the lean paradigm and its application to, and linkages with resilience?
What are the research gaps and prospective research directions for the lean–resilience theme?
The paper is structured as follows.
Section 2 presents the research methodology;
Section 3 reports the findings, followed by discussion of various research contexts;
Section 4 discusses potential research directions and
Section 5 presents the conclusions.
2. Materials and Methods
This research aims to identify and examine the current state of research on the links between the resilience and lean paradigms and then classify this work to uncover potential gaps and discrepancies, along with directions for further research. A literature review is a valid approach to providing an understanding of a field and its development. It is useful for identifying areas where research is required, helping to structure knowledge of a field and develop theory and conceptual content [
23], while providing a new contribution to the context where extensive research already exists [
24]. The literature review in the present paper follows a clear, explicit, reproducible and systematic process which leads to reliable findings that provide the basis for drawing rigorous conclusions [
25]. A systematic literature review is a method that adopts an accurate, transparent and well-defined approach of a sequence of stages to obtain reliable results [
26]. The two research questions posed in the previous section can be answered using a systematic review of the existing literature.
A systematic literature review has the following five sequential phases, proposed by Denyer and Tranfield [
27]: (1) articulating questions, (2) positioning studies, (3) defining categories and selection criteria for study selection and assessments, (4) scrutinizing and synthesis and (5) reporting and utilizing the findings. This process is at the core of a structured and effective literature review. As Saunders et al. [
28] contend, to address the transparency issue in a systematic literature review, the review must explain in detail how its processes were carried out, especially the literature selection, and decisions made about the use of particular search terms and databases.
Figure 1 describes the stages of the systematic literature review undertaken in this paper, and the tools and methods utilized to assist every stage, together with the section of the paper where these are delivered.
2.1. Selection of Databases, Search Criteria and Timing
Academic publications are accessible by way of various database engines, including Web of Science, Scopus and Google Scholar. Opinions about these databases vary, with Falagas et al. [
30] arguing that Scopus is preferred, while Wang and Waltman [
31] contend that the classification of journals on Web of Science is better. This paper uses both the Web of Science and Scopus databases, and Google Scholar is also used as a support tool. Other publisher databases were searched for this study including Elsevier (sciencedirect.com), Springer (springerlink.com), MDPI (mdpi.com), Emerald (emeraldinsight.com), Taylor & Francis (T&F) (tandfonline.com), Wiley (onlinelibrary.wiley.com), Inderscience (inderscience.com), SAGE (sagepub.com), Institute of Electrical and Electronics Engineers (IEEE) (ieeexplore.ieee.org) and the International Group for Lean Construction (IGLC) (iglc.net).
The search period was from 2000 to 2020, which also includes “in press” research that would later be published in 2021. The reason for selecting 2000 as the starting point was that the debate on integrating lean and resilience can be traced to this period. In the engineering domain, resilience can be traced back to the 2000s when Hollnagel et al. [
32] defined engineering resilience as the inherent ability of a system to adapt its functionality in the presence of a disturbance and unpredicted changes. There is also limited evidence that resilience and lean have been examined in the scholarly literature as complementary paradigms since the early 2000s [
33].
The search criteria used for identifying the studies followed the C-I-M-O (context-intervention-mechanism-outcome) framework to establish the exclusion/inclusion criteria of the search strings [
34]. These strings were (lean resilience), (lean risk management), (lean supply chain risk management), (lean supply chain resilience) and (lean resilience-sustainability). This procedure was assisted by including the defined search criteria and eliminating articles that did not have both terms or a relationship among them. This selection and systematic approach ensured the completeness of the procedure. Manual checks were conducted to prevent consideration of duplicate articles within the search strings by reviewing abstracts. Importantly, those articles that did not clearly focus on resilience and lean (e.g., by discussing “lean resilience” within the context of material science, chemistry, and biology) were eliminated. Consequently, lean–resilience related papers, such as Wears et al. [
35], Johnson et al. [
36] and Bombelli [
37], were not included in the review.
Research findings encompassed peer-reviewed papers in English, published in academic journals and the proceedings of international conferences only, as Saunders et al. [
28] argued these resources are the most reliable for literature reviews. In the next step, an in-depth analysis was carried out of how lean and resilience can contribute to risk management. The content analysis technique proposed by White and Marsh [
38] was used to conduct a data reduction process, as shown in
Figure 2.
By applying the preferred reporting items for systematic reviews and meta-analysis (PRISMA) process of Moher et al. [
39], this study initially identified 241 documents through database searching of combined lean and resilience context. Following application of exclusion criteria, 146 were considered for general analysis. Finally, 53 articles were identified as relevant for detailed analysis to answer the first research question by applying the inclusion criteria.
Based on the criteria explained in this section, a final sample of 53 papers referring to lean and resilience was identified and uploaded to NVivo software. Following the extraction of the eligible records, a qualitative literature synthesis was undertaken using NVivo to establish a more holistic conceptual framework to understand lean and resilience interconnections. NVivo was endorsed by Thomas and Harden [
40] as highly efficient software for coding data from full articles. NVivo was used to conduct a thematic synthesis, enhance the outcomes on lean–resilience and deliver an abstracted theoretical factor structure.
2.2. Analysis and Synthesis
To synthesize qualitative research, a large number of methods, including qualitative meta-analysis, meta-ethnography, thematic analysis/synthesis and qualitative comparative analysis can be considered [
38,
40,
41]. Thematic synthesis was used for this paper as it is recommended for analyzing the outcomes from the systematic review of the literature, due to its efficiency in classifying significant recurring themes and structured methods of dealing with data within each theme [
41].
The analysis procedure in this paper followed Garza-Reyes [
29], and the selected articles were initially classified into three main sub-categories (see
Table 1). As resilience and lean paradigms must be synchronized for their implementation, the processes were categorized into supply chain domain or operation/process, based on their micro or macro level, as suggested by Slack et al. [
42], to identify commonalities. These classifications created second and third sub-categories, while the first sub-category included those items that considered resilience and lean from a conceptual perspective. The number of articles classified by sub-category is shown in
Table 1. This initial categorization provided the foundation for coding and specific analysis of the 53 articles, as well as their classification in a sub-category. Features pertinent to lean–resilience were discovered in this way, and new classifications were developed based on these categories and coding, ultimately leading to a concept map in Figure 9. The results of the thematic synthesis are shown in
Section 3, separated into a descriptive section (
Section 3.1) and a concept map (
Section 4.1).
5. Conclusions
In this study, we conducted a systematic review of the literature about the integration of lean and resilience paradigms. Through this review, 53 articles published between 2000 and December 2020 were identified using C-I-M-O framework. The systematic literature review method was deliberately chosen to review a large sample size of articles and improve the reliability of our findings. This method was used to answer two research questions.
The first question asks, what themes have been researched previously on the lean paradigm and its application to and linkages with resilience? The answer to this question, which is developed through diverse content and bibliometric analysis in
Section 3 and
Section 4, is four research themes associated with resilience and lean. These themes address the combination of resilience and lean paradigms in four ways: their application in organizational functions and industries, compatibility with each other, integration with other paradigms and impact on various organizational features such as performance.
The second question asks, what are the research gaps and prospective research directions for the lean–resilience theme? The answer to this question, which is developed in
Section 4.1.5. (Future research paths) is presented through a series of research questions that can help the future researcher to identify possible pathways for future studies.
A general claim found in the research is that the resilience paradigm is imperative for organizations, and it must be aligned with their general priorities of profitability and productivity, particularly for manufacturing, operations management and logistics. Conversely, whereas lean practices aim to minimize all potential wastes in the process, resilient practices seek to minimize the impact of any unexpected event and crisis on the organization and process to bring them back to their initial state before the disturbance took place. Diverse characteristics of the resilience and lean concepts have been examined, and the different deployment of these practices has been proposed as a potential procedure for obtaining alignment. However, the development of this area is still in the early stages, with most of the studies published in the last ten years. This systematic review provides guidance on the topic for scholars and contributes to transparent paths for further studies, particularly for implementing the integrated lean–resilience concept in manufacturing, supply chain, logistics, construction, disaster management and many more disciplines.
While the present research has identified multiple knowledge gaps and future directions, they are not prioritized in any way; all are significant. Despite this, examining an integrated approach for organizational functions and practical advancement in industries would appear to be critical. Defining potential research areas can encourage academics to study specific issues, leading to a better understanding of the dynamics of integrated initiatives. In addition, to disseminate the practical implications of lean–resilience paradigms, this research seeks to provide industry practitioners with a general overview of lean and resilience to develop new knowledge about these paradigms and their practices, and to develop more effective approaches to their implementation.
Finally, while this review has been conducted in accordance with best practice methods, there are two practical limitations. First, the data were collected from different peer-reviewed academic journals and conferences, which excluded the content of master or doctoral theses, unreleased articles, and books. The second limitation was the collection of all papers from English-language journals. Consequently, the systematic review did not encompass journals in other languages.