Statistical process control

Statistical process control methods and possibility of their use to solve quality problems of the output products have been discussed in the article. Variability of the technological process and its effect on the output products quality have been characterized. Situations which claim interference in the technological process have been described. Different types of Shewhart control cards have been considered: simple control cards by variables and alternative attributes, cards with warning boundaries, cumulative sums cards, exponentially weighed moving averages cards. Besides univariate control cards, Hotteling multivariate control cards and cumulative sums cards which are used to control multi-parameter technological process are discussed in the article. Fields of application of different types of control cards are described