Conventionally, improving production efficiency, flexibility and responsiveness has been the primary research focus of production management, while energy consumption has received relatively little attention. Energy consumption plays a more and more important role in the manufacturing environment. This is mainly driven by energy cost and environmental concerns. When the energy system becomes complicated and coupled with ongoing production, it is very difficult to hunt the “hidden treasure” which affects the overall benefit of a manufacturing system. This paper provides a systematic method to search for energy saving opportunities and strategies. We start from dynamic production transient analysis and provide quantitative analysis for identifying energy saving opportunity in a system. Furthermore, energy saving strategy is justified through cost analysis for tradeoffs between energy savings and throughput loss. A case study is conducted to demonstrate its potential on energy savings in a multistage manufacturing system.