There are several examples of automation one comes across daily, simple examples being sewing machines, packaging machines. Such machines are generally equipped to perform in a specific way or to execute specific tasks. A sewing machine is designed to produce specific stitch lengths and likewise a packaging machine is designed to wrap a specific size of the product. When product sizes change some parts of the machine are to be manually changed to accommodate the new size. Such machines are essentially designed to package millions of products of a specific size and are hence special purpose machines. The cost of such a machine is distributed over large sales volumes.

More recently there is a demand for variety. A good example is shirts of a size suiting a given individual. Likewise there is a demand for soaps of various sizes and shapes. This requires machines that can handle various shapes and sizes and every time such a requirement arises one has to stop the machine and readjust or reset some of the links or components to handle the new product. This is a task that is not only time consuming but also requires skill.

Human beings, unlike machines can not only handle tools and products of different sizes and shapes but are also capable of executing a variety of tasks. Engineers have often sought similar capabilities in machines and this has been possible now with the availability of inexpensive microprocessors.

Used in conjunction with special servo-motors, actuators and sensors, the microprocessor has revolutionized automation. It is now possible to build automation devices that can be operated under the guidance of a program. A familiar example is a printer that can be programmed to print the alphabet. A few key strokes would enable the user to change over to a program that enables one to draw diagrams. This capability is extended further through the use of sensors. For example a sensor in the printer does not permit the printing to begin unless a paper is present. These capabilities are extended further and when the machine is able to change its activity to suit a given situation it is called “autonomous”.