Process Variation Analysis Using Empirical Methods: A Case Study

2011 ◽  
pp. 62-65 ◽  
Author(s):  
Heiko Ludwig ◽  
Yolanda Rankin ◽  
Robert Enyedi ◽  
Laura C. Anderson
Keyword(s):  
Process Variation ◽  
Variation Analysis ◽  
Empirical Methods

scholarly journals Assembly Variation Analysis of Aircraft Panels under Part-to-part Locating Scheme

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xia Liu ◽  
Luling An ◽  
Zhiguo Wang ◽  
Changbai Tan ◽  
Xiaoping Wang ◽  
...  
Keyword(s):  
Elastic Deformation ◽  
Assembly Process ◽  
Variation Analysis ◽  
Kinematic Theory ◽  
Statistical Variation ◽  
Variation Propagation ◽  
Fixed Part ◽  
Compliant Parts ◽  
Aircraft Panels

A typical aircraft panel is the assembly consisting of a multitude of thin and lightweight compliant parts. In panel assembly process, part-to-part locating scheme has been widely adopted in order to reduce fixtures. By this locating scheme, a part is located onto the pre-fixed part/subassembly by determinant assembly (DA) holes, and temporary fasteners (e.g., spring pin) are used for joining these DA hole-hole pairs. The temporary fasteners can fasten DA hole-hole pairs in the axial and radial directions of DA holes. The fastening in the radial directions is realized by the expansion of temporary fasteners. Although the usage of temporary fasteners helps reduce the positional differences between hole-hole pairs, their clamping forces thereby may lead to elastic deformation of compliant parts/subassemblies. Limited research has been conducted on such elastic deformation produced by temporary fastener and its influence on assembly dimensional quality. This paper proposes a novel rigid-compliant variation analysis method for aircraft panel assembly, incorporating the deformation in part-to-part locating process. Based on the kinematic theory and linear elasticity deformation assumption, the variation propagation through the locating process, as well as the entire assembly process of an aircraft panel, is formulated. Then, the statistical variation analysis is performed with Monte Carlo (MC) simulation. Finally, the proposed method is validated by a case study. The result shows the deformation in the part-to-part locating process significantly impacts the assembly variations, and our method can provide a more accurate and reliable prediction.

scholarly journals Six Sigma Project in a Vendor Company of Transmission Systems for Automotive Insdustry: A Brazilian Experience

2015 ◽  
Vol 6 (1) ◽  
pp. 100
Author(s):  
Orlando Roque Da Silva ◽  
Alessandro Marco Rosini ◽  
Angelo Pamisano ◽  
Vitória Catarina Dib
Keyword(s):  
Automotive Industry ◽  
Six Sigma ◽  
Process Variation ◽  
Transmission Systems ◽  
Project Cost ◽  
Positive Evidence ◽  
Structural Problems ◽  
Supply Systems

Six Sigma has been gaining more and more space in business as a very effective tool tosolve structural problems by reducing the process variation and supply of products and serviceswithin the needs of customers. The main way that seeks to achieve this goal is through thedevelopment of projects for improvement. In this paper an analysis of a project cost reductiontool in an industry supply systems for the automotive industry is presented. The researchmethodology used in the study is based on case study accompanied by exploratory research.Data analysis provided positive evidence that the factors mentioned influence effectively thesuccess and consolidation of Six Sigma and its tools in the company studied.

scholarly journals Stability of a rock mass using the key block theory: a case study

2020 ◽  
Vol 150 ◽  
pp. 03024
Author(s):  
Y. Zerradi ◽  
A. Lahmili ◽  
M. Souissi
Keyword(s):  
Rock Mass ◽  
Underground Mines ◽  
The Finite Element Method ◽  
Empirical Methods ◽  
Mining Operations ◽  
Initial Equilibrium State ◽  
Eastern Zone ◽  
Geometrical Data ◽  
Key Block

In underground mines, excavating disturb the initial equilibrium state of the rock mass, and therefore require selection of a support in order to control the movement of rocks, avoid landslide and work safely. Thus, the progress of mining operations in the ST2 mineralization, in the eastern zone of the Bouazzer mine, is disrupted because of stability problems. On the basis of field observations and analyzes of core drill, the geological and structural study, carried out in this area, has shown the existence of three types of facies: altered and cracked diorite, cobaltiferous mineralization which is in contact with serpentinites. In fact, the empirical methods such as Barton, Bieniawski and the recommendations of the AFTES have qualified the rock mass as poor, furthermore they proposed as kind of supports: steel arches, shotcrete and rock-bolts. Numerical simulation by the finite element method proved to be very complex due to existence of several types of discontinuities (faults, shistosities and joints).These discontinuities are natural fractures that delimit various shapes and sizes of wedges, which can become detached from the roof or siding of the excavation and collapse under their own weight. Although the empirical methods cited above provide supports for each facies, however, this support is expensive and difficult to implement in practice because it must cover the entire surface of the excavation and thus not allowing to detect stable blocks that do not require a support. For this it was essential to carry out an analysis of wedges to better locate unstable blocks. The treatment of fracturing data has highlighted the presence of five sets of discontinuities of which three sets are principals and the other two are minor joints. Then, while taking into account the geometrical, mechanical data of the discontinuities as well as the geometrical data of the excavation, we were able to detect the shape and the size of the unstable blocks and the sets of discontinuities delimiting them and which favor their sliding and tilting. Thus, we calculated the number of anchor bolts needed to stabilize these blocks in order to ensure an acceptable safety factor. This study shows clearly how a wedge analysis of the rock mass can guide and optimize the support work.

Human Capital from Entrepreneurs’ Perspective – Case Study Świętokrzyskie Voivodeship

2016 ◽  
Vol 42 (4) ◽  
pp. 63-72
Author(s):  
Sylwia Wiśniewska
Keyword(s):  
Qualitative Research ◽  
Human Capital ◽  
Focus Group ◽  
Empirical Research ◽  
Research Method ◽  
Empirical Methods ◽  
The Individual ◽  
Individual Dimension ◽  
Descriptive Method

The aim of this paper is to analyse human capital problems faced by entrepreneurs, on the example of Świętokrzyskie Voivodeship. Both theoretical and empirical methods of analysis are used. The descriptive method of research is used to conduct a survey of the literature on the topic. The notion of human capital is presented, as well as the structure thereof in the individual dimension. Next, the paper includes the methodological premises of the empirical research and defines the research sample. It also discusses the results of qualitative research, which used the research method of a focus group. Finally, research conclusions are drawn, and recommendations are made regarding the possible ways of solving human capital issues faced by Świętokrzyskie entrepreneurs.

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