it may be
possible to achieve some of the potential energy savings in a particular situation simply by changing operating practices, and then achieve the remaining savings with some investment in new or modified facilities. There are obvious advantages in the former scenario (operating changes only): They require no investment, and they can usually be implemented very quickly. However, during a PFD review it is often not possible to determine how much can be achieved using only existing facilities, and how much of the potential savings will require investment in new equipment. Ideas are documented during the review, and evaluate afterward