Quantitative Tools

Quantitative Tools

1. Control Charts

   • It is used to distinguish variations due to assignable or special causes from the random variations inherent to the process
   • Variable control chart
     • - The length or thickness of an element. - It is possible to measure the quality characteristic to be studied. - Variable control charts are more "sensitive" than control by attributes, which is why they are able to "warn us" of possible problems even before they are already relevant
   • Attribute control chart
     • - Number of defective units. - If the inspected product is classified as non-compliant or compliant (defective or non-defective), with respect to the specifications for the characteristic of quality considered. - Allow to classify as acceptable or unacceptable; moreover, they do not usually need very complex measurement systems and are more easily understood by specialists.

2. Pareto chart

   • It identifies the most important problems on which improvement efforts should be concentrated and order resolve them
     • It classifies into two categories the vital few and the trivial many

3. Histogram

   • It distributes a set of data, in a graph of bars attached and each bar represents a subset of the data.

4. Dispersion diagram

   • It describes the joint behavior of two variables, where each case is represented as a point in the plane defined by the variables X-Y

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