# Integrating Sustainable Performance into the Digital Maturity Models for SMEs in Manufacturing
## 3 Literature Review
### Search and Selection Strategy  
First and foremost, the exclusive use of the SCOPUS search engine in this study is justified by its broad multidisciplinary coverage, essential for addressing the various aspects of sustainable performance and I4.0, and its advanced filtering capabilities, which allow for a rigorous and relevant selection of publications. SCOPUS is widely recognised for its comprehensive indexing of peer-reviewed research in engineering, sustainability, and digital transformation, making it particularly suited to our study's focus. Additionally, the use of a single database ensures methodological consistency, aligned with the objectives of this research. While Web of Science and other databases also provide valuable sources, SCOPUS was selected due to its broader coverage of technical and applied research, particularly in the field of industrial engineering. Moreover, SCOPUS's advanced citation tracking facilitates a structured approach to identifying key contributions in the field. The criteria used when reviewing articles to assess their consistency throughout the literature review were partially based on factors such as thematic alignment, academic quality, research currency, methodological robustness, and practical relevance of the results. However, the final selection of articles was guided by the research objectives. Indeed, articles were selected based on their relevance for determining whether the measurement of sustainable performance indicators is appropriate and for compiling the list of information necessary to collect within an SMME to measure sustainable performance levels. This approach ensures that the selection of articles was both objective and directly aligned with the research questions, thereby guaranteeing the reproducibility and reliability of the literature review results. Initially, the literature review was guided by the intersection of the concepts of I4.0, sustainable performance, and SMMEs. The first article search was thus driven by the query: (\"Industry 4.0\" OR \"Industries 4.0\" OR \"Digitalization\" OR \"Digitalisation\") AND (\"Sustainability\" OR \"Durability\" OR \"TBL\" OR \"SDG\") AND (\"Manufacture\" OR \"Manufacturer\" OR \"SME\" OR \"PME\") in the SCOPUS search engine. This search yielded 291 articles, of which 76 had titles addressing sustainability or performance in SMMEs. After reviewing the 76 articles, 10 were ultimately deemed relevant to achieving the objective of this research. The exploratory literature review, in turn, revealed that there were many articles in the literature sharing the concepts of I4.0 and SMMEs but covering only a portion of sustainable performance. To ensure the comprehensiveness of the research, it was relevant to conduct three additional searches related to the concepts of I4.0 and SMMEs, each focusing on one of the individual dimensions of sustainable performance. The following three queries were thus created to enrich the database. First, a search was conducted on the intersection of the concepts of I4.0, economic performance, and SMMEs. The second article search was therefore conducted using the query: (\"Industry 4.0\" OR \"Industries 4.0\" OR \"Digitalization\" OR \"Digitalisation\") AND (\"Economic\" OR \"Financial\") AND (\"Manufacture\" OR \"Manufacturier\" OR \"SME\" OR \"PME\") in the SCOPUS search engine. This search yielded 429 articles, of which 50 had titles addressing financial indicators or performance in SMMEs. After reviewing the 50 articles, 5 were ultimately deemed relevant to achieving the research objective. Secondly, a search was conducted on the intersection of the concepts of I4.0, social performance, and SMMEs. The third article search was thus conducted with the query: (\"Industry 4.0\" OR \"Industries 4.0\" OR \"Digitalisation\") AND (\"Social\" OR \"Public\" OR \"Community\") AND (\"Manufacture\" OR \"Manufacturier\" OR \"SME\" OR \"PME\") directly in SCOPUS. This search yielded 394 articles, of which 24 had titles addressing social performance in SMMEs.