One of the most enjoyable and rewarding lean manufacturing improvement activities is the energy treasure hunt. The booty we claim on these energy treasure hunts include savings by shutting off motors or machines left running, replacing energy inefficient motors, replacing over-sized equipment, fixing leaking compressed air, reducing excessively pressurized air, lighting left on, energy inefficient lights, excess heating or cooling of the facility / water / processing equipment, computer monitors left on and much more. These are only the direct and obvious energy saving opportunities.
Energy treasure hunts are also great ways to reinforce awareness of the seven types of waste and make explicit links to how the 7 wastes contribute to energy losses. All of the 7 wastes cause energy losses but this is something overlooked and the savings are not properly quantified. Overproduction, the mother of all wastes consumes energy by operating equipment to make products we don’t need. This leads to the other wastes being created, such as inventory which needs to be heated, cooled, conveyed, lighted using energy. Transportation of goods uses more energy. Waiting itself may not be the greatest waste, but surely the light, heat and running equipment wastes energy while people wait. Defects waste tremendous energy as all of the energy to produce it is wasted, the product needs to be made again, and many times people spend time correcting, reporting and analyzing the defect which uses energy in a variety of ways. Processing waste creates energy losses when the equipment size and speed are inappropriate to get the job done efficiently. Motion waste is the most challenging one to link with with energy waste because we are talking about human motion, and excessive human motion can cause unsafe work conditions, lower productivity or poor quality which has consequences on energy efficiency.
The tools of the energy treasure hunt are very simple, include tags, walk schedules and defined routes, and visual boards to summarize and track the findings and action plans. Companies with mature lean systems such as strong 5S discipline backed by daily auditing and visual management, TPM programs and early state equipment planning through the production preparation process (3P) can include the concept of energy treasure hunts within these practices rather than just as separate events. Once team-based small group activities and leader standard work has been fully established the energy treasure hunts can be naturally incorporated as part of these monthly activities.
Energy treasure hunts are ideal when it is easy and safe to “go see” the current condition of energy use within a facility or site. When access to observation of the facility is limited (e.g. continuous processing industries) or when the scope of energy use is spread across a wide geography (e.g. logistics), other energy assessments methods can be useful. For instance incorporating energy use as a metric during value stream stream analysis is very helpful for any type of energy use environment.
Whenever reliable data can be collected through metering, statistical process analysis is an excellent way to capture variability and waste in energy use.
The U.S. Environmental Protection Agency www.epa.gov reports that energy intensity, defined as the primary energy consumption per dollar of real GDP, in the U.S.A. dropped by 46% between 1975 and 2005. Recent studies suggest that energy use could be reduced in manufacturing and industrial sectors by 75% with currently available technologies at little cost. This statistic reminds me of the analogy that Taiichi Ohno made in his book Workplace Management about organizations that are like boxers who make themselves too lean even to fight in an attempt to make their weight. Many companies cut back on cost by cutting back on their most value able resource: people.
At the same time the air conditioning is blasting, the hot water in the washroom is scalding, and unused machines are humming. The cost of people is obvious while the cost of energy is often diffuse and not tracked by value stream or zone. When the digging gets rough, throw away the shovel, is what these types of companies seem to be saying. And these treasures aren’t even buried very deep. It just takes people to find them.