HC = ΣV *C / I chemical products i] (11.5)
In many cases, it is enough to follow the trend for a plant based on its produced
units (Iproduction), e.g. per produced engine. If the plant changes production mix or the
type of unit produced, this is not valid. A complement to the production index is
the weight of removed material (Iremoved material) measured in tonnes. This will be a
figure that has to be calculated for each type of material. Often, however, most
departments use only one material type. Most components manufactured in the
investigated plants are made of steel, cast iron or aluminium but it may still be
difficult to compare similar operations for different materials.
Another efficiency or performance parameter is based on installed system size, it
is the turnover time, which is used to evaluate system efficiency for each process fluid
system. It is calculated as the system’s total installed volume divided by the average