Process Capability for a Non-Normal Quality Characteristics Data

2007 ◽  
Author(s):  
S. Ahmad ◽  
M. Abdollahian ◽  
P. Zeephongsekul
Keyword(s):  
Process Capability ◽  
Quality Characteristics

Analyzing processing quality of machine tools via processed product: Example of ball valve processing machine

2020 ◽  
Vol 234 (4) ◽  
pp. 331-341 ◽  
Author(s):  
Kuen-Suan Chen ◽  
Der-Fa Chen ◽  
Ming-Chieh Huang ◽  
Tsang-Chuan Chang
Keyword(s):  
Machine Tools ◽  
Process Capability ◽  
Quality Characteristics ◽  
Process Quality ◽  
Quality Analysis ◽  
Process Capability Indices ◽  
Processing Quality ◽  
Accuracy And Precision ◽  
Capability Indices

Machine tools are fundamental equipment in industrial production, and their processing quality exerts a direct impact on the quality of the component product that they process. Thus, machine tool manufacturers develop various machine tools depending on market needs and processing functions, and the processed component products generally possess multiple smaller-the-better, larger-the-better, and nominal-the-best quality characteristics at the same time. For this reason, this study employed the widely used process capability indices, [Formula: see text], [Formula: see text], and [Formula: see text] to develop a model that can evaluate the process quality of component products and analyze the processing quality of various machine tools. We first converted the process capability indices into functions of the accuracy and precision indices and constructed a multi-characteristic quality analysis chart that can identify the reason for poor process quality in a quality characteristic. Furthermore, considering the fact that the process capability indices can only be estimated, which may lead to misjudgment in the evaluation of process quality, we derived the [Formula: see text] upper confidence limits of indices and the coordinates formed by the corresponding accuracy and precision indices. Manufacturers can then evaluate the process quality levels of the quality characteristics based on where the coordinates falls in the multi-characteristic quality analysis chart. This can more reliably assist manufacturers in monitoring the processing quality of their machine tools and providing feedback to the machine tool manufacturers for machine improvement.

A process capability index for mixed binary-normal quality characteristics

2014 ◽  
Vol 4 (1) ◽  
pp. 66 ◽  
Author(s):  
Amirhossein Amiri ◽  
Ehsan Bahrami Samani ◽  
Hamed Mogouie ◽  
Mohammad Hadi Doroudyan ◽  
Mohammad Hadi Doroudyan
Keyword(s):  
Process Capability ◽  
Quality Characteristics ◽  
Process Capability Index ◽  
Capability Index

scholarly journals PENERAPAN IMPROVED GENERALIZED VARIANCE PADA PENGENDALIAN KUALITAS PAVING BLOCK SEGIENAM

2020 ◽  
Vol 9 (1) ◽  
pp. 87-97
Author(s):  
Nathasa Erdya Kristy ◽  
Mustafid Mustafid ◽  
Sudarno Sudarno
Keyword(s):  
Quality Control ◽  
Production Process ◽  
Control Chart ◽  
Process Capability ◽  
Quality Characteristics ◽  
Quality Characteristic ◽  
Generalized Variance ◽  
Process Capability Analysis ◽  
Capability Analysis

In quality assurance of hexagonal paving block products, quality control is needed so the products that produced are in accordance with the specified standards. Quality control carried out involves two interconnected quality characteristics, that is thickness and weight of hexagonal paving blocks, so multivariate control chart is used. Improved Generalized Variance control chart is a tool used to control process variability in multivariate manner. Variability needs to be controlled because of in a production process, sometimes there are variabilities that caused by engine problems, operator errors, and deffect in raw materials that affect the process. The purpose of this study is to apply Improved Generalized Variance control chart in controlling the quality of hexagonal paving block products and calculating the capability of production process to meet the standards. Based on the assumption of multivariate normal distribution test, it can be seen that the data of quality characteristics of hexagonal paving blocks have multivariate distribution. While based on the correlation test between variables it can be concluded that the characteristics of the quality of thickness and weight correlate with each other. The result of the control using these control chart shows that the process is statistically in control. The results of process capability analysis show that the production process has been running according to the standard because the process capability index value is generated using a weighting of 0.5 for each quality characteristic that is 1.01517. Keywords: Paving Block, Quality Control, Variability, Improved Generalized Variance, Process Capability Analysis

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