Six Sigma is a term used to describe processes operating at the highest quality level with minimum variation while producing less than four defects per one million opportunities (Johnston, 2003). This extremely low defect rate is generally achieved through the application of statistical techniques and other quality improvement tools in a formalized manner. As Johnston (2003) has noted, the term was coined by the Motorola Corporation over a decade ago to identify the target capabilities for processes, a standard set of quality tools to use in pursuit of the goal and the ways in which these tools should be applied.
Today, many manufacturers use Six Sigma as key measures in production, though relatively few companies use them to measure the day-to-day performance of business processes (Johnston, 2003). To succeed and to achieve Six Sigma quality, the establishment of strong relationship between product defects and yields, reliability, cycle time, inventory, schedule and costs must be maintained (Rencher, 2003). Products must first be designed so that manufacturing processes are capable of yielding 99.99966 percent in the product. Thus, the Six Sigma design process translates into perfecting the process so that 99.99966 percent of the products made are defect free. As a result, the Six Sigma design process also decreases design and manufacturing cycle time, decreases inventory, scrap, and rework, and increases profitability (Rencher, 2003).
Andrew Berger (2003) has stated that numerous continuous improvement projects using Six Sigma have been gathering momentum for many years. Six Sigma is often credited with very impressive financial benefits by those companies that have been in the forefront of its implementation. Firms like Motorola, General Electric and Honeywell, according to Berger (2003), claim to have delivered financial benefits of more than $1 billion through Six Sigma while other companies such as Texas Instrume...