Efficiency in engineering operation

Unlike the scientist, the engineer is not free to solve problems which interest him. He must solve problems as they arise, his solution must satisfy conflicting requirements. Efficiency costs money, safety, adds complexity, performance increases weight. The engineering solution is the optimum solution, taking into account many factors. It may be the cheap est for a given performance, the most reliable for a given weight, the simplest for a given safety, or the most efficient for a given cost. Engineering is optimizing.

To the engineer, efficiency means output divided by input. His job is to secure a maximum output for a given input or to secure a given output with a minimum input. The ratio may be expressed in terms of energy, materials, money, time or men. Efficiency is achieved by using efficient methods, devices, and personnel organizations.

The need for efficiency leads to the large, complex operations which are characteristic of engineering. The processing of the new antibiotics in the test-tube stage belongs in the field of biochemistry. But when great quantities must be produced at low cost, it becomes an engineering problem. It is the need for efficiency and economy that differentiate s ceramic engineering from the work of the potter, textile engineering from weaving and agricultural engineering from farming.

Since output is input minus losses, the engineer must keep losses and waste to a minimum. One way is to develop uses for products which otherwise would be waste. Losses due to frictionoccur in every machine and in every organization. Efficient functioning depends on good design, careful attention to operating difficulties, and lubrication.

The raw materials with which engineers work seldom are found in useful forms. Engineering of the highest type is required to conceive, design and achieve the conversion of the energy of a mountain stream into the powerful torque of an electric motor. Similarly, many engineering operations are required to change the sands of the seashore into the precise lenses which enable us to observe the microscopic amoeba in a drop of water. In a certain sense, the successful engineer is a person always trying to change things for the better.