تويت
The production of many products involves both fabrication and assembly activities. Fabrication is the making of the component piece parts that are later assembled into the final product. Fabrication methods include casting, molding, forging, forming, stamping, and machining. Assembly may be manual or automatic. Automatic manufacturing can range from semiautomatic to fully automatic, depending on the number of human operations required. Automatic manufacturing installations may also be called fixed and flexible according to how easily they can be altered to make product variations. These several available modes allow the creation of a mode that draws on all of them—the autofacturing mode, that combination of the manual and the specific types of automatic operations which best achieves the quality, operational, and economic objectives sought.
The selection of assembly mode must be consistent with the design of the product, the personnel skills, the equipment available, and other factors. Manual assembly is suitable for low volume output and relatively short production runs with high product-to-product variations.
Fixed automatic assembly is suitable for high-speed, high-volume production of uniform products. Also called hard, dedicated, or conventional automation, it can produce low-unit-cost items of uniformly high quality once its machinery is perfected and until a product variation is wanted. If a product’s assembly cost is the sum of its setup cost (the cost of getting everything ready to make it) and its run cost (the cost of making it), then manual assembly has a relatively low setup cost but a high run cost, while fixed automatic assembly has the reverse. Flexible automatic assembly is suitable for midrange-volume production with variations in product specifications. Also called soft or programmable automation, it uses robots and other computer-based equipment that are more easily movable and adjustable so as to reduce setup costs and still enjoy low run costs. It fits between fully manual and fully fixed automatic assembly, as shown in Fig.
Autofacturing is a production system that is comprised primarily of automated equipment which is configured as several integrated subsystems, using one common database and computer controls to make, test, and transport specifically designed products at high and uniform quality levels meeting flexible specifications with a minimum of human effort. There are many levels of autofacturing from individual cells, or islands, all the way up to a complete and integrated system. Most situations are somewhere in between, but progressing toward a total system.
Autofacturing is a subset of the overall field of automation. It refers to automated manufacturing activities as distinguished from the many other things called automation, such as data processing, office automation, electronic funds transfers, automated banking, central station telephone operations, airline ticket reservations, and the like.
An autofacturing system is composed of several integrated subsystems. Also, along with other systems such as marketing and distribution systems, general accounting and cost accounting systems, management information systems (MISs), and others, it is a subsystem of the corporation’s overall operating system. All subsystems should be interconnected, complementary, in balance, and integrated into one total system.
