Research Trends and Gaps in Lean Manufacturing and Value Stream Mapping for Oil-Loss Mitigation in the Palm Oil Industry

The palm oil industry continuously seeks to improve production efficiency while minimizing oil losses, which significantly affect crude palm oil (CPO) recovery and overall operational performance. Lean Manufacturing and Value Stream Mapping (VSM) have been widely recognized as effective approaches for waste reduction and process optimization; however, their application to mitigating oil losses in palm oil processing has not been comprehensively investigated. Therefore, this study aims to analyze the development of scientific publications, identify research trends, and determine research gaps related to Lean Manufacturing and VSM for reducin oil losses in the palm oil industry. This research employed a Systematic Literature Review (SLR) integrated with bibliometric analysis using the PRISMA framework. Scientific publications were retrieved from the Scopus database. After screening and applying the predefined inclusion and exclusion criteria, 60 articles published between 2023 and 2026 were selected for analysis. Bibliometric analysis was conducted using VOSviewer and Bibliometrix. The findings reveal a growing research interest in Lean Manufacturing, waste reduction, process optimization, sustainability, and Industry 4.0. Lean Manufacturing and VSM remain dominant research themes, whereas oil losses in the palm oil industry represent an underexplored topic with relatively low research intensity. Furthermore, the research gap analysis indicates that previous studies have primarily emphasized productivity improvement and general waste reduction without specifically addressing oil losses throughout the palm oil production process. This study contributes by providing a comprehensive bibliometric overview, identifying future research opportunities, and proposing a conceptual framework integrating Lean Manufacturing and VSM to support oil losses mitigation and sustainable operational improvement in the palm oil industry.