SIX SIGMA

Six Sigma

Six Sigma

Introduction

Six Sigma is a strategy used within the business to manage quality. It is applied across many sectors. It aims to reduce the amount of defects that occur in products. By reducing this variability in the output of produced items, cost can be reduced or profit increased. Defect elimination is an inherently sustainable goal, as defective products result in wasted resources, wasted energy, and wasted labor.

While Six Sigma has now entered the common language in certain business and manufacturing circles, “Six Sigma” is registered by Motorola, Inc., as a trademark. Originally implemented by Motorola as a statistically based way of improving the defect rate in the manufacturing of electronic devices, Six Sigma has now become widely recognized throughout a variety of industry sectors (Bothe, 2001).

What does six sigma mean?

Manufactured products have specifications that must be met in order for the product to be considered functional and useful. A product needs to fulfill a number of criteria that can often be defined numerically; for example, a nut needs a certain internal diameter and thread in order to securely fix onto a bolt. In statistics, if the “mean” represents the desired specification and the nearest specification limit can be defined as six standard deviations from the mean, then virtually all manufactured products will fit within this spectrum of quality and be considered acceptable. Any process that is said to operate with Six Sigma quality will produce a defect level of less than 3.4 defects per million opportunities.

Any quality management approach assumes that a cultural change can be achieved within the organization and commitment to achieving quality management can be gained from employees at all levels of the organization including top management.

Six Sigma and Sustainability

In order to work toward improving the sustainability of manufacturing operations, it is critical that energy and materials be conserved. When a manufacturing defect occurs, the product is unsuitable for consumption and waste is generated. While this waste may be recycled within the manufacturing system, there will be some embodied energy loss, and additionally there may be some degradation of the material. By eliminating defects in manufacturing, and Six Sigma is one of the methods that can be used to accomplish this goal, materials and energy can be used more effectively (Ross, 2005).

Six sigma hierarchy

As an employee's knowledge of Six Sigma practice develops, they are able to fulfill different quality management roles within their organization. The Six Sigma technique borrows from the parlance of martial arts, to define a hierarchy of skills:

•Yellow Belt: the lowest level of Six Sigma knowledge and applies to an employee who has a basic working knowledge of Six Sigma and who may manage small process improvements but does not lead team projects.

•Green Belt: a Six Sigma-trained individual who, although not working exclusively on Six Sigma projects, has duties that include implementing Six Sigma methodologies in team projects.

•Black Belt: an employee who has been trained and certified in its methods. As a result, all of the duties of this individual include implementing Six ...