Connecting lean and green with sustainability towards a conceptual model

Lean manufacturing has already proven to be an effective management philosophy for eliminating waste in production processes, leading to operational gains. However, nowadays, it is not enough just to obtain economic results, with the environmental aspect being a concern that organizations have been incorporating into their production processes due to stakeholder's pressure in order to increase their sustainable performance. As such, a bibliometric and a structured analysis of the literature were carried out focusing on the connection between lean, green and sustainability concepts. The Web of Science platform was used to collect data, encompassing the period from 1900 to 2020. The carried analyses covered the identification of the most relevant papers, including their authors, as well as their temporal and geographical distribution. There was also focus on the draft of a map to observe an underlying intellectual structure through VOSviewer. The novelty of this research is that, through the gathering of relevant data related to the three concepts considered and their analysis, a conceptual model was proposed consisting of lean-green and sustainability (LGS) tools to achieve superior triple bottom line (TBL) performance. This study pinpointed that in most of the cases where LGS tools have been applied (TPM - Total Productive Maintenance - and 6R, e.g.), there was a positive impact mostly on the economic and environmental pillars of the targeted companies. Although there were also a small number of other cases where it was found that an improved efficiency induced an increased consumption of energy and water, namely by lean tools (SMED Single Minute Exchange of Dies, e.g.), the results demonstrated the capability of lean and green, especially their combination, to enhance sustainability outcomes. Future research should focus on quantifying the effects that LGS tools, in a single way or combined, bring to all TBL pillars, especially the social one, e.g., by developing key performance indicators. The testing of the proposed conceptual model, including its completion, is also encouraged, namely through the evaluation of what is the best combination of LGS tools, considering specific sectors of activity.