Publicado en el sitio de la consultora MCTS (Steve y Pamela Williamson, y Jerry Cornacchio.
JIT presentations often employ the analogy of a stream when describing proper inventory management. Well-managed systems achieve a flow of inventory from raw material to the customer like a smooth river, unimpeded by shoals of scrap or machine breakdown or other problems. This concept did not originate with the Japanese. Henry Ford's River Rouge plant regularly converted iron ore into a Model T in four days. However, in recent years, especially the 1970s, American business has not improved its manufacturing capability quickly enough to maintain a competitive position in cost or quality or market responsiveness or flexibility.
In 1983 APICS began a zero inventory crusade---strongly advocating JIT. Firms such as CM, Ford, Chrysler, Bendix, Harley-Davidson, IBM, Hewlett-Packard, AT&T, and others began the journey even earlier. There has been much progress on regaining competitiveness in recent years. This progress has been achieved by emphasizing continuous improvement, reduced inventories, expanded roles for hourly workers, fewer levels of management, longer term relationships with customers and suppliers, and an emphasis on providing value to the customer, Many American firms are once again at or near world class status. We should remember, however, that complacency is the principle barrier to maintaining world class status. We must adopt the philosophy of Kaizen, continuous improvement. The Japanese underscore the urgency of maintaining competitiveness with a phrase taught to every schoolchild, "Export or Die!" In yesterday's world, export or die was a truism for any island economy. In today's global village, export or die is a truism for all economies.
What is Just-In-Time? / Why is JIT Important?
To prosper---and often even to survive---manufacturing companies must provide value at least equal to that of competitors. Today, manufacturing competition includes plants located in many different parts of the world. For example, some refrigerators sold at major department stores in Canada are assembled in Wroclaw, Poland, using a condenser manufactured in Sao Paulo, Brazil. Much of the world is one big market, with goods crossing many different types of boundaries.
Although international trade always has existed, it has exploded in the last few decades. Improved communication and transportation have been contributing factors, but the primary cause has been dramatically improved manufacturing productivity---with emphasis on both quality and cost. Although Japan has been in the forefront of this advance, South Korea, Taiwan, Malaysia, Singapore, and Thailand have made remarkable strides. Progress is also taking place in Mexico and Brazil, and most Western European countries have continued to improve their industrial capability. In addition, it is not unreasonable to expect that Eastern European countries will improve their competitive position as they revise their economic policies.
These developments and a benign neglect of manufacturing by top management in many North American firms caused foreign trade balance deficits and a lower productivity growth in the United States during the 1960s and 1970s than in many other countries. Some U.S. companies lost market share and others lost markets. The MIT commission on industrial productivity reported a large and increasing balance of trade deficit in automobiles, consumer electronics, machine tools, semiconductors, and textiles (Dertouzos et al. 1989). Continuation of such a pattern can have dire consequences for the quality of life in any country. Foreign debt, currency devaluation, and loss of markets and profits eventually not only affect the ability of consumers to purchase material goods such as toasters and automobiles but also limit a nation’s ability to support health care, the arts, education, and recreation activities. In brief, the standard of living can decrease dramatically. For example, Argentina was a relatively prosperous country at the turn of the century, but today its economy is in shambles. Nearly all citizens suffer when such a change occurs.
The MIT commission observed:
A large continental economy like the United States will not be able to function primarily as a producer of services in the foreseeable future. One reason is that it would have to rely on exports of services to pay for its imports, and this does not seem realistic. In 1987 gross U.S. exports of services, excluding income from overseas investments and overseas sales of government services, were worth $57 billion, whereas the total value of goods and services imported into the United States was about $55 billion. - - , The United States thus has no choice but to continue competing in the world market for manufactures. The ultimate scale of American manufacturing is not known, but it will not be trivial. The important question is not whether the United States will have a manufacturing industry but whether it will compete as a low-wage manufacturer or as a high-productivity manufacturer. (Dertouzos et al. 1989, 39-40)
Clearly it is preferable to compete as a high-productivity manufacturer.
These considerations led many organizations in the United States, Canada, and other countries to examine successful manufacturing organizations in North America and throughout the world to identify the operating characteristics and practices of companies capable of competing in the present worldwide market. The essential characteristics of a such a company are that it produces high quality products at low cost and that it responds quickly to customer requests for delivery, changes in design, and changes in volume, When a company has achieved these goals, it can compete with anybody, anywhere. It is important to understand that both high quality and low cost are relative terms; continuous improvement is needed to maintain high relative quality and low relative cost. Referring to the degree of change needed to achieve world class status in Thriving on Chaos (1987), Tom Peters notes:
Radical changes in organizational structure and procedures are called for, Layers of management must be reduced in most big firms by 75 percent. Product development time and order lead time must be slashed by 90 percent. Electronic/telecommunication linkups to customers and suppliers must be developed posthaste. Just listening to customers and dealers needs to become the norm-and as yet it is not.
Different terms are used to identify the process of improving manufacturing productivity with emphasis on high quality and low cost: the Just-in-Time (JIT) approach, zero inventory, total quality management, world class manufacturing, and the search for excellence. We are using JIT because it seems to have been the first, and all of the essential concepts are inherent to it. The title of the process is not important; adopting the philosophy and pursuing its operating objectives are. This section includes concepts, approaches, and practices that may have originated under the aegis of programs with each of the different labels and titles given to various productivity improvement programs.
miércoles, marzo 07, 2007
Aunque se trata de la introducción al estudio de las técnicas de Just-In-Time (Justo a Tiempo), las claras ideas expuestas fundamentan mucho más que un buen sistema de producción. Quien quiera sacar conclusiones, hágalo: