About quality intervals in assessing the manufacturing technology of products by the accuracy parameter of linear size

Abstract

Among the issues of ensuring product quality, an important component is the assessment of the quality of its manufacturing technology.
The quality of technology is assessed by the quality of the products received. One of the indicators of the quality of engineering products is the linear size of the parts. Any product can be produced using various technologies, but each of them provides not the same quality. High quality is accompanied by increased costs, which in a competitive market is not always acceptable for manufacturers.
Depending on the needs of the manufacturer regarding quality, it becomes necessary to identify a technology that provides the desired quality. The issues of creating a tool for assessing the quality of manufacturing parts by the accuracy of size to determine the gradation of the quality of technology are considered. It is proposed to introduce assessment of technology with intervals of quality.
The research used the theoretical apparatus of probability theory and mathematical statistics. The use of a general model of the distribution of the linear dimensions of parts and the found estimates of its parameters is proposed.
It is shown that the proposed model has three different forms of distribution density with the same theoretical range of estimates of the upper and lower sizes and with the same number of measurements. These forms can identify the quality of technology as high, medium, and low.
Based on the calculations obtained, a gradation system is constructed that determines, for a given volume of measurements, a qualitative characteristic of the technology for manufacturing products.
Using the proposed results makes it possible to analyze the quality of the manufacturing process of products with an increase in their volume. The results obtained allow us to find an estimate of the appropriate amount of manufacturing products with the desired quality. The conducted studies help in resolving issues of quality management of engineering products.