In your own words explain the purpose of quality control in

In your own words, explain the purpose of quality control in production and service operations. What are control charts and how are they used in quality control? What are the two cause of process variation? Describe each one in your own words and provide examples for both.

Solution

The control charts is a form on which determined statistical measures of products properties are recorded as a result of inspection taking randomly samples of products in the determined place of the process. The form of the control chart can be adopted to examining the quality of the process with one statistical measure (single-parametric chart), for example values of the average, or for simultaneous examination the quality of the process with the help of two or of more statistical measures, for example a value of the average and the range

We should exactly determine what parameters of the product will be controlled and on the basis of these evidences select control chart appropriate for our needs. The control charts are used for observation and the registration of the changeability of the characteristic of the researched element of the production process. Their interpretation is based on the normal creation and distribution. Recording result of measurements take place by writing on control charts the value of characteristic reading from taken samples. Such operation allows for fast and effective identifying and eliminating causes disrupting the process

Variations are due to:

a) Results of measurements are evenly distributed around the central line, not crossing admissible area in addition. The process proceeds perfectly. This is an ideal condition where strict control is done

b) Admissible area was crossed the process is disqualified. Here the admissible area is neglected hence quality become poor.

c) Seven next points increase what perhaps will lead to exceeding acceptable limits. Blunting the tool can be a cause.

d) Variation periodically repeating itself to the measured value. An influence of amendments to the daily employer