Quality Control and Statistical Process Control

What this unit covers

The page centres on statistical tools for monitoring and improving quality. The mind map Chapter 10: Statistical Quality Control sets out the big picture: statistical process control, process capability and Six Sigma quality. Several maps on statistics applied to quality control trace the story back to Deming training Japanese engineers in the 1950s, and to Kaoru Ishikawa, who was one of that group.

The basic tools

Many resources deal with the seven basic tools: histograms, control or run charts, scatter plots, check sheets, Pareto charts and cause and effect diagrams. The map Ishikawa's Seven Basic Tools of Quality Control shows how cause and effect diagrams work backwards from symptoms to a root cause. The Quality Tool Belt map then places those tools alongside management, creativity, statistical, design and measurement tools.

Charts, sampling and experiments

For control charts, open Shewhart Charts. It walks through finding the mean and range for each sample group, setting the centre line, and when to build a chart, such as at initial commissioning or after major changes. Western Electric:The Zone Rules adds rules for reading a chart. There is also a quiz and a flashcard deck on acceptance sampling, and flashcards on design of experiments covering screening, factorial designs, randomisation and replication.

A sensible order

1. Start with the Chapter 10 map for an overview.
2. Move to the seven basic tools maps.
3. Work through Shewhart Charts and the zone rules.
4. Test yourself with the acceptance sampling quiz and the quality control quizzes.
5. Finish with the design of experiments flashcards.

Use maps to learn the structure, then quizzes to see what stuck. Go back to the map for anything you miss.

Where it sits

This unit belongs to the Quality Engineering and Management strand of Industrial engineering and quality. Open a map you like and build your own version as you revise.