In the case of Mitsubishi Electric, energy saving has become part of its DNA. There is one key concept which is fundamental to changing the perception of energy usage. Mitsubishi Electric calls this EPU:
the Energy Per Unit produced. It is simply the amount of energy consumed to produce one product.
EPU has two powerful attributes; it allows the direct association of the energy cost to the manufacturing activity and it is also variable/dynamic.
This might not sound so important until you have a production line stoppage and the EPU starts to rapidly increase as energy is consumed but the product is no longer being produced. The second attribute is that it makes it easy to compare production performance between lines, or even factories because the EPU is entirely driven by the efficiency of production, i.e. productivity. And this is why Mitsubishi Electric uses it to benchmark the company but also to drive energy saving activities.
Typically, manufacturers have a very clear idea of the material costs, direct and indirect labor costs, logistics, depreciation, etc. related to their manufacturing processes. But very rarely do they actually know anything other than the headline energy consumption. So the comprehensive approach to this issue is essential. In this case Mitsubishi Electric uses the e-F@ctory concept – it is Mitsubishi Electric’s initiative to extract hidden benefits from existing resources, through integrated automation. The ultimate goal is to improve efficiencies, reduce cost, and increase overall productivity.