Propuesta de valor

Lean production, TQM, and Six Sigma all have similar roots in the continuous improvement and waste elimination movement that began in Japan in the 1950s. Thus, they considerably overlap and, some argue, are essentially the same.14 _{Yet there are distinctions, and practicing lean should not be equated}

to practicing TQM. Lean is a process broadly aimed at increasing value added and eliminating waste, and includes techniques geared toward those things. But eliminating waste cannot be achieved solely through efforts directed at manufacturing. Process improvement and waste reduction require a companywide, integrated effort that includes all functions—marketing, sales, finance, product engineering, purchasing, customer service, accounting—as well as manufacturing, which is the emphasis of TQM and its companywide commitment to quality. While lean production seeks improvement through reduction of waste, TQM seeks improvements that matter most to customers. As an example, manufacturers used to think that inspection to sort out defects was an improvement because it reduced bad products going to the customer. It did reduce waste and it was an improvement. Nonetheless, since sorting out defects did not involve finding the root causes of defects (and allowed the causes to stay in the system), the improvement was not fundamental. Fundamental improvement means eliminating the sources of problems, not just the symptoms, and it requires changes in functions besides manufacturing, including product design and purchasing. Lean production in theory seeks to eliminate wastes that might mask problems, but TQM provides the mechanisms for finding the root causes of waste so they can be eliminated.

Because lean systems run with little slack or inventory, the production process must be reliable, stable, and predictable. The biggest detractor from reliability and stability in processes is variability in production schedules, procedures, materials, machine functioning, and worker skills. TQM and in particular Six Sigma provide the procedures and tools for identifying and eliminating the sources of excess variability. Since companies are always changing products and processes, and since the manufacturing environment (both internal and external to the company) is always changing, any source of variability, once identified and removed, will soon be replaced by others. Using TQM and Six Sigma, the new sources of variability will be identified and dealt with before they cause problems.

The joint application of lean production principles with TQM and Six Sigma methodology has become so common that a term has been coined for it: lean Six Sigma.

Summary

Quality can be defined from two perspectives: that of the customer and that of the producer. The customer-focused quality approach starts by taking the customer’s perspective, then works backward to translate customer requirements and needs into the producer’s perspective, which are considerations about product design and manufacturing that will result in a product or service that meets or exceeds customer requirements. Orienting the design and manufacture of products to meet these requirements is referred to as quality of design and quality of conformance, respectively.

Total quality management is an organization-wide management approach committed to quality and continuous improvement. It is also a process in which an organization is continually aware of the changing needs and expectations of customers, of challenges posed by the competition, and of threats and opportunities in the business environment. TQM is also a management framework for integrating the efforts of sales, marketing, finance, engineering, manufacturing, purchasing, suppliers, and customer service around determining what customers want and need, and delivering the products and services that satisfy them. It is a concerted, continuing effort to broaden and deepen worker involvement in quality and improvement efforts and to give frontline and support workers the skills, training, education, and support necessary for them to meaningfully contribute to those efforts.

Any organization adopting lean production must also be involved in TQM initiatives and employ quality of design methods such as concurrent engineering and DFMA, and the process control methods of SPC. Whereas lean production provides techniques and philosophy for process improvement through waste- reduction efforts, TQM provides methods, teamwork, organization-wide participation, and customer-focus so that these improvement efforts address fundamental problems and result in better products and services from the customer’s perspective.

Notes

1. D. Garvin, 1987. Competing on the eight dimensions of quality, Harvard Business Review November- December (1987): 101–109.

2. See C. L. McNair, World-Class Accounting and Finance (Homewood, IL: Business One Irwin, 1993).

3. B. Flynn, Managing for quality in the U.S. and in Japan, Interfaces 22, no. 5 (1992): 69–80.

4. K. Henderson and J. Evans, Successful implementation of six sigma: Benchmarking at General Electric Company, Benchmarking: An International Journal 7, no. 4 (2000): 278.

5. M. Harry, 1997. The Nature of Six Sigma Quality (Schaumburg, IL: Motorola University Press, 1997), 1–2.

6. The strict interpretation of Six Sigma is somewhat more involved than described here. Though the example assumes the population mean coincides with the target value, in reality it is difficult to get the process mean to coincide exactly with a given target value. Thus, the defect rate of 3.4 per million allows that the population mean can be as far away as 1.5 standard deviations from the target value. Nonstatisticians need not worry about this detail; the point remains: Six Sigma means high quality and a defect rate of practically zero.

7. Notice the similarity of DMAIC to the general improvement process of PDCA (plan–do–check–act).

8. K. Ishikawa, What is Total Quality Control: The Japanese Way [trans. D. Lu] (Englewood Cliffs, NJ: Prentice-Hall, 1985), 37.

9. D. Muther and L. Lytle, Quality education requirement, in Total Quality: An Executive’s Guide for the 1990s, ed. Ernst & Young Quality Improvement Consulting Group (Homewood, IL: Business One Irwin, 1990), Chapter 7, 105–107.

10. For example: D. Garvin, 1988. Managing Quality: The Strategic and Competitive Edge (New York: The Free Press, 1988); G. Bounds, L. Yorks, M. Adams, and G. Ranney, Beyond Total Quality Management (New York: McGraw-Hill, 1994); Ernst & Young Quality Improvement Consulting Group, Total Quality: An Executive’s Guide for the 1990s (Homewood, IL: Dow-Jones Irwin, 1990); S. George and A. Weimerskirch, Total Quality Management: Strategies and Techniques Proven at Today’s Most Successful Companies (New York: John Wiley & Sons, 1994).

11. R. Chang, When TQM goes nowhere, Training and Development Journal 47 (1993): 22–29.

12. R. Hayes and G. Pisano, Beyond world calls: the new manufacturing strategy, Harvard Business Review January–February (1994): 77–86.

13. L. Tatikonda and R. Tatikonda, Top ten reasons your TQM effort is failing to improve profit, Production and Inventory Management 37, no. 3 (1996): 5–9.

14. J. Dalhgaard and S. Dahlgaard-Park, Lean production, six sigma quality, TQM and company culture, The TQM Magazine 18, no. 3 (2006): 263–281.

Suggested Readings

R. Amsden. SPC Simplified: Practical Steps to Quality. Portland, OR: Productivity Press, 1998.

R. Connors, and T. Smith. How Did That Happen?: Holding People Accountable for Results the Positive, Principled Way. New York: Portfolio Hardcover, 2009.

J. Liker, and D. Meier. Toyota Talent: Developing Your People the Toyota Way. New York: McGraw-Hill, 2007.

T. Stapenhurst. Mastering Statistical Process Control: A Handbook for Performance Improvement Using SPC Cases. Burlington, MA: Butterworth-Heinemann, 2005.

G. Taylor. Lean Six Sigma Service Excellence: A Guide to Green Belt Certification and Bottom Line Improvement. Fort Lauderdale, FL: J. Ross Publishing, 2008.

Questions

1. What is meant by the customer’s perspective of quality? The producer’s perspective? How do these perspectives relate to customer-focused quality?

2. What are the eight dimensions of quality as identified by Garvin? What are other possible dimensions of quality? Select three products and discuss how the dimensions apply to each.

3. What is the meaning of quality of design? Quality of conformance? Quality of performance and service?

4. In what ways is employee involvement and employee ownership in the quality concept cultivated in TQM organizations?

5. What is concurrent engineering?

6. What is design for manufacture and assembly (DFMA)? What is the relationship between DFMA and concurrent engineering?

7. What is meant by Six Sigma? What is the statistical interpretation of Six Sigma? 8. Describe the steps in the DMAIC procedure.

9. Describe SPC. What is the main purpose of SPC?

10. What is a control chart? What are its main features and how is it used? 11. What does it mean for a process to be stable?

12. What does it mean for a process to be capable?

13. Many large corporations have demonstrated their commitment to TQM by requiring that every employee attend seminars on quality concepts, and know the tools for problem solving and SPC. Everyone belongs to a problem-solving group, and groups are expected to meet once a week. Comment on this approach to TQM.

14. What is quality at the source? What role do frontline workers have in quality at the source?

15. What are the difficulties in implementing TQM? What distinguishes companies that say they are TQM companies from those that are TQM companies?

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