Table 2.1: Improvements in Machine Tool Technology Since the 1970s
Increased accuracy due to
▪Thermal effect compensation
▪Geometric compensation through CNC
▪Real-time compensation for tool wear
▪Dynamic compensation for die-height (for effects of thermal and speed vaiations)
Improved operations due to more capable CNC:
▪Download of instructions rather than tape
▪Remote diagnostics
▪Visual representation of cycle progress at the machine
▪More accurate contouring
▪Programming at CNC machine
▪Automatic die changes
Improvements in components of machines
▪Switch from hydraulic drives to electric drives
▪Linear Drives
▪Higher spindle speeds
▪Variable spindle speed used in conjunction with electric drives
▪Faster die changes and automatice bolster/die changers
Improved tool materials provide longer tool life and allow more demanding machining:
▪Coated carbides
▪Cubic Boron Nitride (CBN) Grinding wheels
▪Ceramic tools
Increased capabilities of machining centers:
▪Greater tool storage
▪Ability to handle more pallets
▪Live tool stations on turning centers
Multiple operations performed with a single machine set-up
Combining processes in one machine: mill, turn, grind
High-speed presses
Wire electro-discharge machining
Waterjet machining
Laser machining
Flexible manufacturing systems (an arrangement of machines interconnected with a transport system and both being controlled by a computer system)
Programmable logic controllers
Stereolithography ( a rapid prototyping process whereby a 3-D object is created using cross-sectional data from a computer-aided design file and “printing” it with a solid-object printer)
Improving handling of parts:
▪Robotics and handling of parts of rotation
▪Automatic loading and unloading of parts from presses
Automobiles illustrate this trend. Consumers spend more on cars and light trucks than any other durable good. According to the Bureau of Labor Statistics, vehicle quality between 1967 and 1998 increased at an annual average rate of 2.2 percent. This means that a car built in 1998 has twice the quality as one built in 1967 in terms of per formance, reliability, durability, and warranty. Today, owners of new cars produced by U.S. companies experience fewer than 30 problems per 100 cars during the first year of ownership, compared with 104 per 100 cars in 1980.
Higher quality means fewer repairs and longer useful life (Table 4.2). Car maintenance costs dropped 28 percent between 1985 and 1998, translating into a sav ings of $21 billion in 1998 alone. As a result of higher quality, the median age of cars in operation today is over eight years, compared with 6.5 years in 1990 and less than five years in 1980. Yet the average mileage traveled by cars increased from 9,500 miles a year in 1985 to over 11,000 miles today (Chart 4.3).
Advances in manufacturing technology and machine tools have also delivered savings to consumers through major improvements in the fuel efficiency of cars and light trucks during the last 15 years. Today’s passenger vehicles are more powerful and more economical than those of 25 years ago, and they are saving consumers tens of billions of dollars annually in fuel costs alone.
The story of the automobile industry is no fluke. Similar quality improvements and dollar savings are seen in other durable consumer goods. For example, new, more precise and flexible machine tools have enabled the manufacture of the scroll compressor, making it possible to increase the energy efficiency rating of air conditioners and heat pumps nearly 40 percent since 1981; the energy rating of refrigerators jumped 100 percent during the same period. These improvements saved consumers nearly $20 billion in electricity costs during 1997 alone (Chart 4.11).
MACROECONOMIC BENEFITS
In addition to the many machine tool advances that have enabled manufacturers in various industries to produce better products faster and cheaper, improvements in manufacturing technology have also delivered important gains to the economy as a whole in at least four major areas.
First, and of greatest significance, the dramatic turnaround in manufacturing helped fuel America’s economic expansion during the 1990s. After accounting for inflation, the average annual rate of growth of real GDP in durable goods industries between 1992 and 1997 was a remarkable 7.6 percent, more than twice the rate for the overall private economy. During the decade from 1987 to 1997, durable manufacturing grew at a 4.0 percent average annual rate, still significantly higher than the private economy as a whole. And according to the Congressional Research Service, increases in manufacturing output have more than twice the downstream impact on the economy as output increases in other sectors of the private economy such as services.
Second, advances in manufacturing technology have improved the quality and prosperity of the workforce by making it necessary for employers to provide workers with more training. Training is often needed because although today’s machine tools are simpler to operate, the tasks they perform are more complex. Workers who improve their skills through training qualify for higher wages and improve their living standards while enhancing manufacturing productivity.
A third heretofore unappreciated benefit of the improvements in manufacturing technology has been to reduce the peaks and valleys of the U.S. business cycle by reducing inventory fluctuations. Better machine tools have helped to shorten process times and aided Just In Time inventory management procedures. In the past, inventory fluctuations have often triggered economic recessions.
Finally, manufacturing improvements have again made the U.S. a powerhouse in the global marketplace. After bottoming out in the early 1980s, the quantity of manufactured goods exported from the U.S. grew at nearly 12 percent annually between 1986 and 1992, while those of leading global competitors lagged. German exports of manufactured goods grew at only 4 percent, for example, and Japan’s grew at just 3.5 percent. Over the 10 year period from 1986 to 1996, U.S. exports of manufactured products grew at an average annual rate of 10 percent, while those from Germany and Japan averaged a mere 4 percent and 2.5 percent, respectively.
CONCLUSION AND RECOMMENDATIONS
The dividends to the U.S. economy created by advances in manufacturing technology are not captured by productivity measures alone. There are other important ways in which the restructuring of the nation’s manufacturing capabilities have generated significant economic benefits for producers of durable goods, the consumers who buy their