THE USE OF MULTILEVEL DISCRETE PRODUCT QUALITY MEASURES AND QUALITY VALUE FUNCTIONS IN STATISTICAL QUALITY CONTROL

摘要

In the majority of acceptance sampling and statistical process control techniques, a single characteristic of an item is used to evaluate its quality and one of two basic types of product quality measures is typically used: attributes or variables. However, there are many situations in which product quality is best described by classifying a single characteristic of the item using three or more discrete levels. A multilevel discrete product quality measure is a function that assigns a numerical value to such an item corresponding to the level in which it is classified. A basic structure for acceptance sampling plans and control charts that incorporate the use of multilevel discrete product quality measures is defined. Such methods utilize a quality value function, which assigns a numerical value to an item based on the classification it receives from the multilevel discrete product quality measure. The probabilistic behavior of the defined multilevel acceptance sampling plans and multilevel control charts is also described.