# Key Performance Indicators for Food Supply Chain: A Bibliometric and Systematic Literature Review
## 4 Discussion  
### Theoretical Implications  
From a scientific point of view, the present study provides a comprehensive bibliometric analysis of performance metrics in the FSC, highlighting the key trends and contributing to some gaps in the literature, and ultimately, laying the groundwork for future research aimed at improving the efficiency and sustainability of this vital sector.  
On the basis of the set of analyses made in the previous Section, an answer to the RQs can be delineated. As regards the RQ1 (\"How is the research on KPIs for FSC characterized?\"), it can be observed that the general trend in time of the publications is growing, with a relevant quota of empirical studies (68 publications), followed by case studies (43)  
Figure 15: Combinations of sustainability KPIs.  
and analytical models (39). The paper with the highest number of citations is a study describing a chance-constrained model for the multi-supplier inventory routing problem, with 206 citations at the time of writing, followed by [57; 58], with 196 and 97 citations, respectively. This suggests that the topic of performance measurement in the FSC is increasingly being studied taking real data from the field. The source with the highest publication numbers is _Agricultural Systems_ with five documents. The majority of papers reviewed are from Italy and the United Kingdom, with 14 and 12 papers, respectively, in line with the importance of agri-food industries in those countries. With respect to the authors, only four researchers published more than three papers on KPIs in the FSC within the sample. It is interesting to note that the analysis did not show any particular collaboration among these prominent authors.  
Regarding the RQ2 (\"What are the most frequent and persistent topics over time, and how do they relate to main research themes?\"), the most common keywords in the sample of papers turned out to be key performance indicators, supply chain management, performance, and sustainability, as expected since they correspond to the terms used for the queries. In addition, outcomes highlight that the number of keywords has progressively increased in time, obviously in line with the increase in the number of papers. Trend of the keywords' classification by period confirms the increased importance of performance measurement in the FSC, as well as the progressive attention to sustainability issues in that context. Other topics whose importance has progressively increased in time refer to simulation-based techniques and energy-related issues. Strong relationships between these topics and those relating to performance measurement, supply chain management, and their FSCs were also highlighted.  
From the results of the content analysis (RQ3), nine main types of products treated in the FSC were identified. Specifically, agricultural products are the most spread in the sample analyzed, followed by papers dealing with dairy and meat products. In an FSC, three different areas can be identified, i.e., supply, production, and distribution [23]. The FSC phase with the highest number of contributions is production, in contrast to the above finding (66 papers), followed by the combination of more phases and the distribution process, with 26 and 25 studies, respectively. Looking at the supply process, the combination of multiple activities appears to be the most developed, followed by growing, while processing is the most analyzed activity in the production area, followed by combinations of several activities within the same paper. Finally, transportation and retail are the two activities that characterize distribution. The KPIs were classified into three macro categories, namely, economic, environmental, and social, and the combination of more than one category of KPIs prevails, followed by the economic perspective, confirming the involvement of the industrial level.