Quality management has been the most rapidly developing field of management studies and practice for decades. Total Quality Management and Six Sigma are the primary concepts in this area that help to evaluate and improve the overall performance of companies. While TQM and Six Sigma derive from the initial prerequisite that quality is the top priority of any organization, they have some differences concerning methodology and vision of the quality management purposes.
Six Sigma is defined as “a business strategy that seeks to find and eliminate causes of errors or defects or failures in business processes by focusing on outputs that are critical to customers” (Muralidharan 558). It was developed as a production management concept by Motorola Corporation in 1986 and popularized in the mid-1990s after Jack Welch applied it as a key strategy in General Electric (Andersson, Eriksson, and Torstensson 283).
Six Sigma concept suggests that the quality of each process in the organization should be improved, and defects and statistical deviations in operating activities should be minimized. The concept implies the use of various quality management techniques, including statistical methods. It requires the top management of the company to set measurable goals and desired results and to create working groups responsible for the solution of quality problems and improvement of quality assurance processes. Moreover, it is important to promote Six Sigma business culture and to develop relationships with the customers based on Six Sigma philosophy (Pesic, Lepojevic, and Zlatic 222).
As a methodology, Six Sigma is a statistically based measurement scale that shows the process performance; it uses the notions of defects and opportunities for defects. Sigma (σ) represents a statistical standard deviation. The maturity of the production process in is described as the σ-rating deviation or the percentage of defect-free products. The quality the quality management process at 6σ level gives 99.99966% output without defects (yield), which means that there is no more than 3.4 output defects for 1 million operations.
The company’s goal is to carry out all the processes so that for any parameters of any process the σ index will be no less than 2,0. When calculating Six Sigma level, first one needs to calculate DPMO (Defects per Million Opportunities) and find the result in the standard conversion table (Tennant 16).
Comparing Six Sigma with TQM, one may note that often TQM is seen either as a predecessor of Six Sigma or a component that “provides tools and techniques to bring about cultural change and process improvement within an organization” (Tennant 8).
Other researchers, on the contrary, consider Six Sigma a “prime ingredient of TQM” (Klefsjo, Bergquist, and Edgeman 175). Andersson, Eriksson, and Torstensson suggest that TQM is oriented more on customers and their loyalty while Six Sigma prioritizes ensuring no defects and improvement of financial performance (290). Regarding methodology TQM provides such stages as “plan, do, study, act”, while Sis Sigma works according to such stages as “define, measure, analyze, improve (design) and control (verify)” (Andersson, Eriksson, and Torstensson 290).
Six Sigma provides a higher level of operational integration and focuses not only on the stabilization of quality but also on its improvement. Moreover, Six Sigma requires the results of each project to be measurable and numeric. Decisions should be made only on the basis of verifiable data with no dubious assumptions (Pesic, Lepojevic, and Zlatic 223).
Another fascinating peculiarity of Sis Sigma is that it divides all the participants of quality management process into several categories; different categories of employees participate in different types of training. The agents of Six Sigma may be Champions and Sponsors (top management and process owners), Master Black Belts (people with the highest technical and organizational skills, department leaders), Black Belts (team leaders); Green Belts (project leaders); Yellow Belts (team members) (Muralidharan 108).
Let us take Air Arabia as an example to calculate the level of Six Sigma for its operations. The statistics of flights and arrivals from August 15, 2015, to October 15, 2015, will be used. During this period, 2579 flights by key Air Arabia routes were conducted. Of those flights 66% (or 1702,14) arrived on time and 34% (828,28) were late (12% late, 7% very late and 12% excessively late) (“Air Arabia On-Time Performance Rating”). Let us calculate DPMO for flight operations = 1 000 000 x (Total defects/Total opportunities) = 1 000 000 x (828,28/2579) = 321163,242. Looking up for an approximate result in the Six Sigma conversion table (“Abridged “6-sigma” Conversion Table”), we will find out that for such amount of defects per 1 000 000 the yield is 65,60% that stands for 1.9 sigma level.
Overall, it can be seen that Six Sigma is an innovative and progressive approach to quality management. Six Sigma as a methodology and management strategy provides a solid foundation for the establishment of efficient corporate quality control. The statistical methods and general quality improvement measures are harmoniously combined in Six Sigma, which makes it easy to conduct the thorough analysis. Six Sigma appears to be a new improved variant of Total Quality Management, which makes it for the organization to reach the best results in the competitive environment.
Abridged “6-sigma” Conversion Table n.d. Web.
Air Arabia On-Time Performance Rating. 2015. Web.
Andersson, Roy, Henrik Eriksson, and Håkan Torstensson. “Similarities and Differences between TQM, Six Sigma and Lean.” The TQM Magazine 18.3 (2006): 282-96. Print.
Klefsjo, Bengt, Bjarne Bergquist, and Rick Edgeman. “Six Sigma and Total Quality Management: Different Day, Same Soup?” International Journal of Six Sigma and Competitive Advantage 2.2 (2006): 162-178. Print.
Muralidharan, K. Six Sigma for Organizational Excellence: A Statistical Approach. New Dehli, India: Springer, 2015. Print.
Pesic, Marija, Vinko Lepojevic, and Vladimir Zlatic. “Six Sigma vs. Total Quality Management – Presence in World and Serbian Economy.” Facta Universitatis 8.2 (2011): 221-233. Print.
Tennant, Geoff. Six Sigma: SPC and TQM in Manufacturing and Services. Aldershot, UK: Gower, 2001. Print.