Manufacturers have options when considering the incorporation of automation into their processes. The correct mental approach to the implementation of automation is to start with the product and work back to through the automation process. The type of product and volume dictates whether the manufacturer should utilize hard (fixed) or soft (flexible) automation.
Hard automation is used for a specific production purpose where the processes are fixed. It is best suited for automated equipment that mass produced high volume products with few alterations or little changeovers. This type of automation has a high initial investment and high production rates, most typically automated assembly line machines.
The Society of Mechatronics Engineering & Technology (“SOMETECH”) points out that each of the operations in a fixed sequence is usually simple and involves a plain linear or rotational motion, for example, or a combination of two such motions. Despite the simple operations involved, it is relatively difficult to make changes in the product design. Advantages of hard automation, according to SOMETECH, include low unit cost, automated material handling and a high production rate. The disadvantages are a high initial investment and the relative inflexibility in accommodating product changes.
The bridge: programmable automation
A type of automation that adds flexibility is programmable automation. SOMETECH notes that the production equipment is designed with the capability to change the sequence of operations to accommodate different product configurations. A program—set of coded instructions—controls the operation sequence so that the system can read and interpret the program. New products can be designed and their specs entered into the equipment. Examples are numerical controlled machine tools, industrial robots and programmable logic controllers.
Advantages of programmable automation include flexibility that allows design variations and its suitability to batch production. Disadvantages include a significant investment in general purpose equipment and a lower production rate than fixed automation.
Programmable automation could be considered a bridge between hard and soft automation, the latter of which provides the greatest flexibility of any type of automation. In contrast to hard automation, soft robotic automation (flexible automation) is reprogrammable and reconfigurable. Robots that handle small batches of product and suit product changes are an example.
Soft automation can be used to produce a variety of parts with virtually no time lost for changeovers from one part style to another or for multiple small batches of a single product. No lost production time results when reprogramming the system. Advantages include continuous production of variable mixtures of product and flexibility to accommodate varying product designs. Disadvantages are a medium production rate, high long term production costs and a high unit cost compared with hard automation.
As Matt Charles wrote in a recent blog post on the website of industrial automation provider Cross Company, “What is Flexible Automation?,” the Tesla Motors Factory in Freemont, CA utilizes soft automation. Although it builds this high-tech car, it could build just about any product. The “veritable robot army” features hundreds of robot arms that perform tasks such as metal-bending and assembly. Robot vehicles carry car chassis around and robot painting arms open and car doors to spray around them. The robots themselves typically have no sensing ability and rely solely on their mechanical repeatability. The overall system is programmed for flexible automation, though.
Both fixed and flexible automation have their advantages, so proper planning is important. The customer, stage of product life cycle and competitiveness of the market dictate which type of automation to tool your facility for. Obviously, more sophisticated customers and more mature product types will force your design manufacturing lines. Newer types of products do not experience the same competitive pressures as more mature ones—at least for a while. So there is a place for more homogenous, mass-produced products. Product design just depends on these factors.
The important thing is to be in touch with your markets and your customers. The stakes are very high when it comes to capital investment—and the margin for error in today’s global economy is very slim.