An Evaluation of Research Interests in Vertical Farming through the Analysis of KPIs Adopted in the Literature

Vertical farming has gained increased attention in recent years due to its capacity to reduce the environmental impact of agricultural production in terms of water consumption and soil and fertilizer usage. In the literature, many works describe and evaluate applications of vertical farming. However, no work addresses the issue of classifying the KPIs for vertical farming and highlights both the most assessed aspects and the lack of evaluations. The main contribution of this study is to conduct a literature review to identify and classify the KPIs used in vertical farming. To this aim, we first proposed a methodology to define the KPI categories. Then, we identified the KPIs used in the literature, and we classified them according to the defined categories. Finally, we analyzed the obtained results. As a result, a collection of 78 KPIs were compiled and organized into the proposed categories. The analyses on the frequency of the KPIs allow us to conclude that the KPIs related to productivity are the most used as compared to those related to sustainability and quality. Furthermore, very few papers perform a cross-category evaluation. This study underscores the necessity for a more balanced consideration of productivity, quality, and sustainability in the context of vertical farming.