Quality control is a critical concept in every industry and profession. The survival of your job and of your company depends on your ability to produce a quality product or service. For most people, quality is associated with the idea of a product or service that’s well done, looks good, and does its job well. Quality product is one that lasts, holds up well under use, and doesn’t require constant repair. A quality product or service should meet a high standard in many areas, such as form, features, fit and finish, reliability, and usability. As products and services evolve, consumer expectations tend to increase so that yesterday’s quality product becomes tomorrow’s junk. Quality revolves around meeting customer expectations, expectations that may be stated or implied. One action that sums up quality from a business perspective is when the customer returns after the sale and the product doesn’t. The statistical definition of quality is a little more precise than other definitions, such as the customer-based concept, and is based on mathematics. When you measure quality statistically, you look for variation in a measurement between what the customers asks for and what you produce. The less variation you have, the higher the quality of your product or service. All processes have some natural variation; you use statistics to detect abnormal variation that could cause you to produce a bad product or service. You can also use statistics to avoid testing every item that you produce. By testing a sample of what you make or deliver, you can use statistics to measure its quality and find out whether it meets customer requirements the statistical definition of quality is a little more precise than other definitions, such as the customer-based concept, and is based on mathematics. When you measure quality statistically, you look for variation in a measurement between what the customers asks for and what you produce. The less variation you
References: http://www.britannica.com/EBchecked/topic/564167/statistical-quality-control Pyzdek, T, "Quality Engineering Handbook", 2003, McGraw-Hill International Editions www.questdiagnostics.com