Sustainable Manufacturing Performance Indicators for a Serial Production Line

Current manufacturing facilities lack proper performance indicators that can accurately pinpoint areas of energy inefficiency on the manufacturing line. This paper establishes new indices that utilize readily available, real sensor information from the production line, such as buffer levels, machine throughput, etc., to find the machine that is the least energy efficient. This is the machine that causes the line to waste the most energy without producing parts. The energy structure of the production line is analyzed to better understand the complex system dynamics and to find the root cause of the energy inefficiencies. A baseline energy consumption is established, which is the least amount of energy that is needed to produce a certain number of parts on the line. Using this knowledge, the new sustainable manufacturing performance indicators are defined to properly monitor the performance of the line. These indices utilize the energy structure to illustrate the static (energy used when there are no downtime events) and dynamic (energy lost due to downtime) portions of the energy consumption. The concepts of the downtime energy bottleneck and the rated power bottleneck are introduced and proven analytically. These methods are verified using simulation studies in Simulink/MATLAB.