Bootstrap Analysis of the Production Processes Capability Assessment

Abstract

The high customer requirements for appropriate product quality pose a challenge for manufacturers and suppliers and also cause them many problems related to ensuring a sufficiently high product quality throughout the entire production cycle. For the above reasons, it is so important to assess the capability of monitored processes, and shaping, analyzing and controlling the capability of processes is an important aspect of managing an organization that uses a process approach to management. The use of an appropriate method to analyze the course of production processes is a necessity imposed by quality standards, e.g., ISO 9001: 2015. That is why it is so important to propose a quick and low-cost method of assessing production processes. For this purpose, a method of assessing the capability of the manufacturing process using bootstrap analysis was used. The article presents the analysis of inherent properties of the production process based on the results of measurements of the characteristic features of the process or the characteristics of the manufactured products (process variables) for the shafts with grooves. The main goals of the work are to develop a procedure for determining process capability based on the bootstrap method, including criteria for the classification of production process capability; to develop the criterion values for confidence intervals of production process capability; as well as to demonstrate the practical application of bootstrap analysis in manufacturing. Moreover, comparative analyses of process capabilities using bootstrap and classic methods were carried out. They confirm both the narrowing of the confidence interval when using the bootstrap method and the possibility of determining a better estimator of the lower limit of this range compared to the results obtained using the classic method. The tests carried out for the unit production of shafts with grooves showed that the analysis of the process capability for measuring tests n = 10 is possible. Finally, new criterion values for the assessment of process capability for the bootstrap method were proposed. The model for assessing the capability of production processes presented in the paper was implemented in low-volume production in the defense industry.

Measuring capability of a Poisson process: Relative goodness of the estimates obtained by different approaches

“…Since ̂ is a point estimate obtained from sample data, it is necessary to construct confidence interval (CI) of the capability index for inference purpose, especially when the sample size is relatively small. In literature, many works (Chou et al, 1990;Zhang et al, 1990;Kushler and Hurley, 1992;Nagata, 1991;Nagata and Nagahata, 1994;Peng, 2010;Stoma et al, 2019) are reported on the construction of confidence intervals of estimated capability indices. But all these works assume that quality characteristic of interest follows normal distribution.…”

Tolerance analysis for automobile transmission shaft based on minimum cost and reliability target

“…The assessment criteria of process capabilityis shown in Table 4. 44, 45 As can be seen, when C p < 0 . 67 and 0 . 67 < C p < 1 . 0 , the process capability is insufficient, thus failing to meet the technical requirements of quality. And when C p > 1 . 67 , the process capability is surplus, thus causing unnecessary manufacturing cost for enterprises.…”

Influence of the Compliance of a Technological System on the Machining Accuracy of Low-Stiffness Shafts in the Grinding Process

“…The low stiffness of such parts, which is lower than the stiffness of the machine tool, can (under certain conditions) cause vibrations and the occurrence of factors that disrupt and destabilize the machining process [ 23 , 24 , 25 , 26 ].…”