Six Sigma (6σ) is a business management strategy that uses concepts from statistical quality control. Six Sigma was originally developed for large manufacturing companies to ensure as few defective units as possible; in official 6σ literature, the aim is no more than 3.4 defects per million.

Although the Six Sigma program is a highly structured system with multiple levels of management, it can still be adapted to small manufacturing operations with few, but dedicated employees. The underlying principles behind Six Sigma can be applied to any small business to improve operations.

The first part of implementing Six Sigma is identifying the variables in your manufactured products, i.e., what can vary from unit to unit. Ask yourself what the acceptable range of variation is. You need to know at what point a variation becomes a defect in the eyes of the customer.

Next, identify variables in your manufacturing process, particularly the ones that you have control over. There can be physical variables, such as temperature or time, and there are of course human variables.

Learn how to compute and interpret some basic statistics from data sets. This data is collected from samples of the products and manufacturing processes. In Six Sigma, or any other method of statistical quality control, the 3 most important measures are the mean, median, and standard deviation.

Understand that the standard deviation of a sample tells you how clustered or spread out the measurements are. A low standard deviation means that most of the measurements are very close to the average; a high standard deviation means that the measurements are all over the place.

When you do quality control checks and find that the units have too much variation, everyone on your team needs to be aware of the problem, and commit to finding solutions.

Train your employees in correct methods of sampling and data collection, as well as how to correctly interpret data. The underlying statistical concepts of Six Sigma are simple enough that most employees can grasp them, even if they have a limited math background.

Assign your employees to different levels of quality management. You don't necessarily have to use the martial arts terminology of Six Sigma (green belt, black belt, champion, etc.) when you adapt the principles to your small business. The important thing is to have a set chain of command when it comes to identifying problems and finding solutions.

Always keep your employees informed of quality control checks and their results. Schedule short monthly meetings to discuss updates and recent findings. One of the core principles of the Six Sigma methods is that everyone involved in the manufacturing process is also involved in reducing the number of defects.