Category Archives for Qualitypedia

Quality Assurance (QA) vs. Quality Control (QC)

There is a lot of misunderstanding when it comes to Quality Assurance and Quality Control. Many times these two terms are used interchangeably. This post summarizes the similarities and differences between Quality Assurance (QA) and Quality Control (QC). Let’s start with the official definitions of Quality Assurance and Quality Control as defined in ISO 9000:2015.Quality Control:Part of […]

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Causes of Poor Quality

Poor Quality The market is customer-centric. Competition is very high. Still, most of the companies face the problem of poor quality. In spite of various quality models, quality improvement processes and methodologies the issue of poor quality is there. Why is it so? What are the causes of poor quality? Causes of poor quality may […]

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Understanding Quality – Definitions and Dimensions

The challenge in defining quality is that it is a subjective concept, like beauty. Everyone has a different definition based on their personal experiences. Definitions The totality of characteristics of an entity that bear on its ability to satisfy stated and implied need. Quality is the ongoing process of building and sustaining relationships by assessing, […]

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History of Quality

22 January 1901 Sir John Wolfe-Barry (the man who designed London’s Tower Bridge) instigated the Council of the Institution of Civil Engineers to form a committee to consider standardizing iron and steel sections. 1911 Frederick W. Taylor published “The Principles of Scientific Management.” 1924  Walter A. Shewhart, a statistician at Bell Laboratories, developed the control charts, and principles of […]

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Seven Quality Tools – Scatter Plot

Sometime around 1950, Quality Guru Ishikawa proposed seven basic quality tools. One of these seven tools was the Scatter Plot. Scatter plot is used to show the relationship between two variables visually. The simple academic example could be to show the relationship between the outside temperature and the ice cream sale. The scatter plot could […]

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5 S

A 5-step process for organizing and standardizing the workplace, summarized by five words or phrases beginning with S: Seiri (Sort) Seiton (Set in order) Seiso (Shine) Seiketsu (Standardize) and Shitsuke (Sustain) It is a methodology for creating a clean, safe, orderly, high performance work environment.

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AOQ – Average Outgoing Quality

Average Outgoing Quality (AOQ): The expected average quality level of an outgoing product for a given value of incoming product quality.AOQ plot represents the relationship between the quality of incoming and outgoing materials. When incoming lots are very good, the outgoing quality will be good.When the incoming lot is very bad, then also the outgoing quality […]

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Average Outgoing Quality Limit AOQL

  ​Average Outgoing Quality (AOQ) plot represents the relationship between the quality of incoming and outgoing materials. When incoming lots are very good, the outgoing quality will be good.When the incoming lot is very bad, then also the outgoing quality will be good because poor lots get reinspected and fixed. See the graph showing the relationship between […]

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Dodge Romig Sampling Plans

Plans for acceptance sampling developed by Harold F. Dodge and Harry G. Romig. Four sets of tables were published in 1940:single sampling lot tolerance tables,double sampling lot tolerance tables,single sampling average outgoing quality limit tables anddouble sampling average outgoing quality limit tables. ​The above video is from my ASQ CQE exam preparation course. To learn Acceptance […]

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