Investigating the contribution of the lean approach for a sustainable supply chain

Purpose Due to the increasing demand for integrating sustainability issues within business, also manufacturing Supply Chains are paying more attention to improve their performance in terms of the Triple Bottom Line and of the three Ps ( People, Profit and Planet). Lean Approach is one of the most known methods to reduce inventories and wastes (Ohno, 1998; Womack and Jones, 1996). Such wastes reduction impacts directly on the companies' costs but, at the same time, may positively impact also People and Planet. Nonetheless, the potential of Lean Approach in improving Supply Chain sustainability is still far from being clearly analysed. Design/methodology/approach Out of the five principals identified by Womak and Jones, in this paper we want to focus on one of the most relevant distinctive element of the Lean Approach: the flow. In order to analyse the impact of such element, we modelled a complex Supply Chain, composed by three echelons and between one and four nodes for every echelon. The main performance indicator measured are the inventory level (t! hat is linked to profit and to energy consumption) and number of deliveries( that is linked to fuel consumption, air pollution and costs). Originality/value The contribution of this paper to the body of knowledge is three fold. The first contribution is the quantitative analysis of the performances simulating a complex Supply Chain. Davis et. al (2011) show that in existing literature there are very few studies that analyse a Supply Chain composed by more than 2 echelons. The second contribution in this paper is the analysis of a Supply Chain with capacity constrains at all the nodes. Davis et. al (2011) highlight that in the existing literature almost none research study simulates a Supply Chain with capacity constrains in more than one echelon. The third contribution is a better understanding of how Lean Approach can improve Supply Chain sustainability and to measure the related performances. In particular the paper analyses the improvement in term of Profit and Planet impact. The research study has been carried out under different conditions of demand variability in order to test the significance of the results under different customer demand conditions.