Whether you’re new to the quality and continuous improvement arena or a seasoned expert seeking detailed information on a specific quality topic, you should find what you need in our Glossary of Terms.

Explore the concepts, tools, applications and technical terms that make up the world of continuous improvement.

Sigma

Sigma is the terms used to describe the Greek letter used to represent the standard deviation of the population.

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Sigma Level

A commonly used measure of process capability that represents the number of standard deviations between the process centre and the closest specification limit.

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Single Piece Flow

Single Piece Flow is a production strategy in which individual units progress as a batch of one unit through each of the associated process steps with continuous flow in the forward direction and without rework.

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Six Sigma

Developed by Motorola and made famous by GE, Six Sigma is a methodology to identify and reduce variability and thus improve overall quality and cycle times. Six Sigma refers to a program to that includes leadership processes, business systems, tools, methods, and aims to achieve the goal of eliminating all forms of wastage to improve organisational performance. It is a disciplined methodology of defining, measuring, analysing, improving and controlling the quality in every one of the companies products, processes and transactions.

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Spaghetti Diagram

A Spaghetti Diagram, also called a physical process map, is a layout diagram of the work area that illustrates the path followed by materials or parts through the facility. It is used to highlight excessive amounts of material transport or employee movement while following steps described in a logical flow map or process flow chart.

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Standard Deviation

The Standard Deviation is a term used to represent a commonly used measure of variability or (spread) in a data set or population. It is equal to the square root of the variance.

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Statistical Process Control (SPC)

Statistical Process Control (SPC) is the use of basic graphical and statistical methods for analysing and controlling the variation of a process, thus continuously improving the process.

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Statistics

Statistics is the term used to describe numerical measures obtained from a sample, as opposed to parameters, which are numerical measures of a population.

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Stem-and-Leaf Diagram

Stem-and-Leaf Diagram is a graphical means of displaying data. It is similar to a histogram but provides more specific information about the elements within a class (or stem).

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