Energy value stream methods with auxiliary systems

The energy and costs reduction are crucial in industries, especially in energy-intensive firms, due to the increase of the competitive pressure and environmental awareness. Moreover, in the recent years many researchers and practitioners have strived to implement Lean Production methods in order to reduce wastes and improve the production performances of industrial systems. This research is focused on the application of Value Stream Mapping (VSM) method to energy consumption, named Energy Value Stream Mapping (EVSM). This research begins with a literature review on the EVSM methods, in order to identify the common and different characteristics and to evaluate the applicability of these methods in the real industrial context. The analysis of these characteristics reveals few attentions to auxiliary systems, even if often they play a significant role from the energy point of view for several energy-intensive firms. In order to fill this gap, we introduce a new method, which permits to identify corrective actions from the current state map observation including the energy consumption of the auxiliary systems. In particular, we draw a new energy line, named auxiliary energy line, which shows explicitly the energy consumption of the auxiliary systems. The overlapping of the process energy line and auxiliary energy line permits to identify immediately corrective actions (e.g. better synchronisation between manufacturing processes and auxiliary systems). In order to explain the proposed method, we show its application to an energy intensive process