TEXT: Industrial Engineering and Automation

One distinction between a mechanical engineer and an in­dustrial engineer is that the former deals with individual machines while the latter deals with machines in combination as part of a system. Industrial engineering is concerned with problems such as manufacturing processes and plant layout.

Industrial engineers must make the most efficient use of plant and equipment to achieve the highest possible degree of productivi­ty. Originally this was conceived entirely in the mechanical terms of what machines could do and how they should be arranged. Now it is known that the effectiveness of the workers in the system must also be considered. The industrial engineer is therefore often in­volved in labor relations.

Industrial engineering in practice if not in name was born at the beginning of the machine age. People like Newcomer, Watt, and Pickard had to be involved not only in the invention of machines but in their application and installation. Throughout the eighteenth and nineteenth centuries the use of machines for all kinds of manufacturing (beginning in most countries with textiles) multiplied many times. We have mentioned the belt drives com­mon in factories where steam engines powered other machines. These dangerous belts are an example of the problems with which industrial engineers dealt and the solutions they evolved.

A major advance in twentieth century manufacturing was the development of mass production techniques. Mass production refers to manufacturing processes in which an assembly line, usual­ly a conveyor belt, moves the product to stations where each worker performs a limited number of operations until the product is assembled. In the automobile assembly plant such systems have reached a highly-developed form. A complex system of conveyer belts and chain drives moves car parts to workers who perform the thousands of necessary assembling tasks.

Mass production increases efficiency and productivity to a point beyond which the monotony of repeating an operation over and over slows down the workers. Many ways have been tried to in­crease productivity on assembly lines: some of them are as super­ficial as piping music into the plant or painting the industrial ap­paratus in bright colors; others entail giving workers more variety in their tasks and more responsibility for the product. Some automobile companies have experimented with giving individual workers complete responsibility for assembling an entire car; this obviously requires an extraordinarily high degree of skill.

These human factors are important considerations for in­dustrial engineers who must try to balance an efficient system of manufacturing with the complex needs of workers.

Another factor for the industrial engineer to consider is whether each manufacturing process can be automated in whole or in part. Automation is a word coined in the 1940s to describe pro­cesses by which machines do tasks previously performed by people. The word was new but the idea was not. We know of the advance in the development of steam engines that produced automatic valves. Long before that, during the Middle Ages, windmills had been made to turn by taking advantage of changes in the wind by means of devices that worked automatically. A major development in textile manufacturing was the loom developed in 1801 by Joseph-Marie Jacquard, a French inventor. Intricate patterns woven into the cloth were controlled by steel cards with holes which were forerunners of the modern computer punch card.

We now use the term automation for specific techniques com­bined to operate automatically in a complete system. These tech­niques are possible because of electronic devices, most of which have come into use in the last thirty years. They include program, action, sensing or feedback, decision, and control elements as com­ponents of a complete system.

The program elements determine what the system does and the step-by-step manner in which it works to produce the desired result. A program is a step-by-step sequence that breaks a task into its individual parts. Some steps in an industrial automation pro­gram direct other parts of the system when and how to carry out their jobs.

The action elements are those which do the actual work. They may carry or convey materials to specific places at specific times or they may perform operations on the materials. The term mechanical handling device is also used for the action elements.

Perhaps the most important part of an automated system is sensing or feedback. Sensing devices automatically check on parts of the manufacturing process such as the degree of heat or the thickness of a sheet of steel or paper. This is called feedback because the instruments return or feed back this information to the central system control.

The decision element is used to compare what is going on in the system with what should be going on; it receives information from the sensing devices and makes decisions necessary to maintain the system correctly. If some action is necessary the decision ele­ment can give instructions or commands to the system.

The control element consists of devices to carry out the commands of the decision element. They may be many kinds of devices: valves that open or close, switches that control the flow of electrici­ty, or regulators that change the voltage in various machines; they make the necessary corrections or adjustments to keep the system in conformity with its program.

Automation was first applied to industry in continuous-process manufacturing such as refining petroleum, making petrochemicals, and refining steel. A later development was computer-controlled automation of assembly line manufacturing, especially those in which quality control was an important factor.

An industrial engineer working with automated systems is part of a team. Many components of the system, such as computers, are electronic devices so electronic engineers and technicians are also involved. Many of the industries in which automation has proved particularly suitable—chemicals, papermaking, and metals processing—involve chemical processes, so there may be chemical engineers at work too. An industrial engineer with expertise in all these fields may become a systems engineer for automation projects thereby coordinating the activities of all the members of the team.