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Mathematical Models of Process Capability
Horník, Petr ; Hübnerová, Zuzana (referee) ; Bednář, Josef (advisor)
Firstly, we deal with the verification of normality and other necessary prerequisites needed in this thesis. We also introduce transformations to converse non-normally distributed data to normal and continue with capability analysis. We describe the design of control charts, useful tools to assess process stability. They help us to eliminate assignable causes and leave only chance causes in process. We obtain process in control state. Finally, we introduce both capability and performance ratios for both normal and non-normal data, and analyse some of their properties. At the end of the thesis, we prove acquired knowledge by performing capability analysis of real process.
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Evaluation of statistical quality control (SPC) in solving the stability of processes in die castings
Hejduk, Oldřich ; Morávková, Jitka (referee) ; Čech, Jaroslav (advisor)
The aim of the theoretical part of this thesis is to describe the system of the aluminium casting alloys, with focus on the aluminium castings used for die casting. In this part of the thesis the different methods of the quality management are described. The practical application of these methods is described in the experimental part of this thesis, in which we focus on the evaluation of the statistical quality management and the process stability of the die casting parts of the selector mechanism cover. This part of the thesis also contains suggestion for the QFD method for this cast.
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Stability of the production process of railway base plates.
Szmek, Tomáš ; Fiala, Alois (referee) ; Koška, Petr (advisor)
The master’s thesis is focused on process monitoring using statistical process control SPC tools. It is designed as a guide for the implementation and use of control charts in the manufacturing process of the base plates, which would ultimately be conducive to improving and stabilizing the process. The theoretical parts are the basic attitudes and practices methodology of SPC, especially classical Shewhart control charts. The next section describes the current status in Strojírny Třinec, a.s. and the manufacturing process of the base plates. Followed by application of control charts for a given quality features and analysis using statistical software. Based on the evaluation are findings and recommendations for long-term monitoring of the defined quality features.
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Optimization of production process
Nováková, Veronika ; Krásová, Anna (referee) ; Fiala, Alois (advisor)
The aims of this dissertation are to analyze the current state of process control, to identify the product range in selected organization and to design the process planning methodology to ensure an optimal implementation. Optimization is understood as costs minimization while keeping an acceptable continuity of supply. The dissertation contains a description of technological and non-manufacturing processes of brick products, as well as the summary and description of the basic tools of quality management.
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Statistical analysis in quality management
Chlebounová, Klára ; Knobloch, Josef (referee) ; Zahálka, Jiří (advisor)
The goal of this thesis is to create a literary research on the methods of statistical data processing in the field of quality management and to make their overview along with the possibilities of using them. A practical example shows how to determine manufacturing process stability and qualification determining, using the Shewhart’s control chart and capability indexes. This methodics should serve as a guideline for manufacturing process evaluation. As a brief summary of generally used statistical data processing methods, this thesis should serve all, who are engaged in quality management.
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Statistics Control of Process Described by Attributive and Continues Variable
Blachut, Vít ; Martišek, Karel (referee) ; Bednář, Josef (advisor)
The principle of the statistic hypothesis testing is explained in the first part of this bachelor thesis. Specifically, there is explained into depth the independency test for discrete probability distribution and its possible application on the real data. The second part of this bachelor thesis is dedicated to the monitoring of the stability process, using the control charts that are primarily used for assessing the process to be stable or beyond control. The focus is especially on chosen construction diagrams deduction. The suitable diagrams are then applied on the real process data, and later there are implemented tests of definable causes. The bachelor’s thesis was supported by project from MSTM of the Czech Republic no. 1M06047 Center for Quality and Reliability of Production.
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Control charts based on Bayes approach
Michálek, Jiří
An algorithm for detecting changes in the behaviour of a random variable based on the Bayes approach is suggested in the report and then is applied to construction of control charts for averages and standard deviation
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The Six Sigma methodology
Zajícová, Hana ; Jarošová, Eva (advisor) ; Malá, Ivana (referee)
Bachelor thesis deals with the desription of the statistical foundations and individual steps of Six Sigma, which are descibed by the DMAIC model. The thesis focuses on statistical process control and control charts. The main goal is to evaluate the possible use of control charts for attributes, namely the control chart for fraction nonconforming or p-diagram and to describe its properties expressed by the operating characteristic (OC). The influence of the sample size on the OC curve is examined. The last part of this theses deals with the desription of the xi-diagram as an alternative of the p-diagram. The properties of this alternative and classical p-diagram are compared.
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