Introduction:
There are two categories of tools and techniques used in quality improvement - Ishikawa's seven tools and the seven new tools for managing quality.
Ishikawa's tools for quality improvement:
Ishikawa's tools and techniques are based on statistical techniques. This is because he argues, like many others, that quality cannot be managed and improved upon without use of statistics. He has categorized the statistical techniques which can be used in the area of quality improvement in three categories.
Elemental statistical techniques
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Pareto analysis;
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Cause and effect diagram;
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Stratification;
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Check sheets;
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Scatter diagram;
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Graph and Shewart control chart.
Intermediate statistical techniques
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Theory of sampling surveys;
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Statistical sampling inspection;
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Various methods of statistical estimation and hypothesis testing;
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Methods of utilising sensory tests;
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Methods of experiment design.
Advanced statistical method (using computers)
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Advanced experimental design;
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Multivariate analysis;
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Operations research methods.
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The seven elemental statistical techniques are perhaps considered the most widely used tools.
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Ishikawa recommends their use to everyone in the organisation.
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His experience shows that 95% of the encountered quality problems can be solved by using the seven elemental techniques.
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It is important, according to Ishikawa, that everyone learns how to use the basic techniques from operator level, to the CEO.
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He argues that the reason for the competitive gap between Japan and the West is that the latter tended to leave the area of quality control to a minority of people within the organisation, considered to be specialists in statistical analysis.
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In Japan however, because quality is everybody’s responsibility, statistical techniques tend to have a much wider usage.
