Performance ratings are also important for the proper sizing and selection of machinery and equipment. Owners and managers need to determine how much a machine can do and how well a machine does do what it has been designed to do. In other words, how efficient is the machine. Inefficient machine use and operation increases operating expenses and decreases potential profits. The concern for quality of machine performance needs little explanation.
Mechanical efficiency evaluates energy conversion and energy converters.
Performance efficiency describes the quality of work done by a machine. An example of performance efficiency would be harvesting efficiency. Another type of efficiency is field efficiency. Field efficiency is the comparison of the time a machine actually spends doing what it was designed to do compared to the total time the machine was in operation. To see how field efficiency and performance efficiency is calculated.