Browse Topic: Six Sigma

Items (144)
A Study on the Development of Aerostructures Design for Assembly Guidelines and Their Effective Use to Proactively Identify Opportunities for Improvement in Mitigating Common Defects of the Aerostructures Assembly2020-01-00093/10/2020
An Aircraft’s assembly process plays a vital part in its design, development and production phases and contributes to about half of the Total cost spent in its entire product lifecycle. Design For Assembly (DFA®) principles have been one of the proven effective methodologies in Automotive and Process industries. Use of DFA® principles have resulted in proactively simplifying and optimizing engineering designs with reduced product costs, and improved efficiencies in product design and performance. Standardization of Assembly guidelines is vital for “Design and Build” and “Build-To-Print” manufacturing supplier organizations. However, Standardizing design methodologies, through use of proven tools like Advanced Product Quality Planning, (APQP) are still in the initial stages in Aerospace part and process design processes. Thus, there is a tremendous opportunity for research on the application of the existing DFA® guidelines to optimize Engineering Aerospace Assembly processes aiming to simplify, standardize design methodologies by building on existing industry practices which have a common platform for design communication and are easy to adopt within the existing process/systems. This technical paper is to discuss the framework for application of DFA® principles and design guidelines specifically aimed for engineering optimization of Aerospace Assembly Process Designs. The Aerospace DFA® implementation framework proposed in this paper is based on the study on the application of the existing DFA® guidelines proven and used in other Process industries to Aerospace Part and Process Design and development. This paper collates the findings, experiences and learnings gained during the study collated from a research point of view using Six Sigma methodology DMAIC and DMADV. This paper also focuses on the use and publication of this research outputs on Aerospace industry applicable DFA® guidelines, which can be used as a reference for emerging Aerospace designers in their future and current designs.
Rajamani, Mani RathinamPunna, Eshwaraiah
A Dynamic Fault Tree Approach for Time-Dependent Logical Modeling of Autonomous Flight Systems2019-01-13583/19/2019
This paper addresses the urgent need for adequate methodologies to use in analyzing autonomous flight systems, including Unmanned Aircraft. These systems are inherently dynamic and require analysis that is explicitly time dependent. Autonomous flight systems are becoming more commonly used, especially for Part 23 aircraft including Business (Corporate) and Regional Jets or Unmanned Aircraft deployed in hazardous environment/situation. Such systems are expected to make their own decisions under uncertain conditions caused by potential system structure changes when entering a new flight phase or switching to a new system configuration due to system degradation or failure(s) [1]. This paper highlights significant modeling errors that can arise in analyzing dynamic scenarios where these time dependencies are ignored. Model-based solutions are provided by incorporating a time-dependent algebraic formalism into Fault Tree Analysis (FTA) and Dependency Diagram (DD) with updated descriptions in SAE ARP4761A and ARP4754B (Note: These are currently under development). A Dynamic Goal Tree (or alternatively, a Dynamic Dependency Diagram) provides an effective implementation of the time-dependent logic for dynamic system analysis analyzing autonomous flight systems which are inherently dynamic since decisions need to be made without human input in a very short time. The safety analysis for autonomous flight systems, including Unmanned Aircraft, can be performed by extending the traditional phased mission analysis, thus the potential system structure changes for different phases in a flight mission can be expressed by a Dynamic Fault Tree (DFT), or alternatively, a Dynamic Goal Tree (DGT), or Dynamic Dependency Diagram (DDD) [2].
Wang, John
Complexity as a Measure of the Difficulty of System Diagnosis in Next Generation Aircraft Health Monitoring System2019-01-13573/19/2019
To develop the Next Generation Aircraft Health Monitoring System (NGAHMS), complexity as a measure of the difficulty of diagnosis, or troubleshooting, of a system is explored in this paper. The results presented can be applied to significantly improve safety and human factor design as an important as aspect of risk engineering and management. This is accomplished in system architecture design by quantifying the system structure’s effect on system complexity as well as the number of components which make up the system. For developing the NGAHMS to make flying even safer, more fuel efficient, and more predictable, model-based safety assessment methods such as Fault Tree Analysis (FTA) and Dependency Diagram (DD) with updated descriptions in SAE ARP4761A and ARP4754B can be used to minimize the average number of airborne inspections to find the Minimal Cut Set (MCS) causing an aircraft failure. Since, based on previous research, this average number of airborne inspections is proven to be lower-bounded by the entropy of cut set importance, the system complexity measure can be used to efficiently estimate how difficult it is to find the actual MCS. This state-of-art safety technique facilitates diagnosing faults effectively, and thus obtain full flight envelope protection for the Next Generation of Air Transport. As a measure for system complexity, this entropy function presents an intrinsic feature of the system, providing the basis of establishing rigorous design principles to diagnose safety-critical faults and thus to cancel their effects systematically through NGAHMS.
Wang, John
Application of Six Sigma Methodology to Improve Product Quality in Injection Molded Parts at Supplier End in Motorcycle Industry2017-01-50119/29/2017
Process Parameters play a vital role in product quality of Injection Molded components. Variation in process parameters will lead to Injection Molded manufacturing defects like Sink Mark, Flow Mark, Silver Streak, Flash, Warping, Weld lines, Jetting, voids, Short Shot & Bubbles. This manuscript is innovative because suppliers (Tier 1 and Tier 2) do not use DoE for standardization of their process parameters in Injection Molding and High Pressure Die Casting. They do trial and error method to arrive at the process parameters which is error prone and time consuming. The variation of process parameters can be optimized using Six Sigma approach, a structured methodology which is Process focused & data driven approach. The purpose of this paper is to present through a case study how the concepts of Design of Experiments, which is a part of Six Sigma Methodology can be used for improving the Injection Molding Process at supplier end reducing defects & hence improving Quality at supplier which stops 100% BOP inspection and segregation when the parts reach the OEM. Here one of the products in Motorcycle Industry has been taken which has 100% Sink Mark defect & resulting in 100% rework. By following the six sigma DMAIC approach and using tools like SIPOC, PMAP, Fish Bone Diagram, Cause and Effect Matrix & Design of experiments to optimize the process parameters at supplier Injection Molding Machine through cross functional team approach. The result has proved that the quality of the product in automotive Industry can be improved by using Six Sigma Approach. This approach can be used for all suppliers and all OEMs or can be horizontally deployed in the Injection Molding Process and High Pressure Die Casting Process to reduce defects and improve product quality by reducing process variation.
Shankaranarayana, Raviprakash
Efficient Procedure for Robust Optimal Design of Aerospace Laminated Structures2017-01-20589/19/2017
Innovative aircraft design studies have noted that uncertainty effects could become significant and greatly emphasized during the conceptual design phases due to the scarcity of information about the new aero-structure being designed. The introduction of these effects in design methodologies are strongly recommended in order to perform a consistent evaluation of structural integrity. The benefit to run a Robust Optimization is the opportunity to take into account uncertainties inside the optimization process obtaining a set of robust solutions. A major drawback of performing Robust Multi-Objective Optimization is the computational time required. The proposed research focus on the reduction of the computational time using mathematic and computational techniques. In the paper, a generalized approach to operate a Robust Multi-Objective Optimization (RMOO) for Aerospace structure using MSC software Patran/Nastran to evaluate the Objectives Function, is proposed. A Multi-Objective Differential Evolution Algorithm with a K-NN surrogate model and named MODE-LD+SS-KNN, is used. The robust evaluation is obtained via a Quasi Monte Carlo Method using Sobol sequence (QMCM), the uncertainties due to material and manufacturing process are modeled via Composite Micromechanics Theory. Example of applications presented include the optimization process for a composite flat plate for minimum weight and maximum uniaxial buckling load. The proposed approach is compared with classical Robust Multi-Objective Optimization method in terms of computational time and a reduction up to one order of magnitude has been pointed out. The computational time reduction makes the Robust Optimization a more suitable choice in comparison with non-Robust Optimization when uncertainty should be included in the optimization loop.
Noziglia, FrancescoRigato, PaoloCestino, EnricoFrulla, GiacomoArias-Montano, Alfredo
A DFSS Approach to Optimize the Second Row Floor Duct Using Parametric Modelling2017-01-01763/28/2017
The main function of mobile air conditioning system in a vehicle is to provide the thermal comfort to the occupants sitting inside the vehicle at all environmental conditions. The function of ducts is to get the sufficient airflow from the HVAC system and distribute the airflow evenly throughout the cabin. In this paper, the focus is to optimize the rear passenger floor duct system to meet the target requirements through design for six sigma (DFSS) methodology. Computational fluid dynamics analysis (CFD) has been used extensively to optimize system performance and shorten the product development time. In this methodology, a parametric modeling of floor duct design using the factors such as crossectional area, duct length, insulation type, insulation thickness and thickness of duct were created using CATIA. L12 orthogonal design array matrix has been created and the 3D CFD analysis has been carried out individually to check the velocity and temperature. The impacts of each design parameters and levels have been analyzed extensively and best combination of design parameters have been found out for the rear floor duct to meet the target requirements. Physical testing is carried out for the optimized floor duct design by making proto parts for the optimized design. There is a good correlation agreement between simulation and test results for the optimized design. Parametric modelling of floor duct significantly aids in reducing the manual design time for simulation by 40% and the DFSS approach helps in finding out the optimized design parameters of floor duct during the design phase of new programs. This methodology can be followed for optimization of duct systems to shorten the product development cycle of the program.
Vasanth, B.Putcha, UdaySathish Kumar, S.nukala, RamakrishnaGovindarajalu, Murali
Engineering Productivity Increase with Organization Architectures2017-01-02483/28/2017
Motivation - Ambiguous product targets, a global market, innovation pressure, changing process requirements and limited resources describe the situation for engineering management in the most R&D organizations. Achieving complex objective with limited resources is a question of performance. Performance in engineering departments is highly correlated to the existing capability of the engineering staff. When the reduction of engineering effort in development projects becomes additional goal for the management, an increase of engineering productivity is required. International engineering sites are established globally to push the capacity limits and to increase the productivity by the accessing big employment markets of engineering talents. By solving the conflict of limited resources and complex engineering goals, a need organizational challenge occurs - global co-engineering. Co-engineering is the extension of simultaneous engineering by the distribution of tasks and responsibilities in a global organization. Different to other global enterprise functions, like sales, the individual engineering staff takes over global responsibilities independent of their own localization. Systems are designed, constructed, implemented or tested in one region for the product release in a different region. Contribution - This technical report analyzes the challenges of engineering management in a global co-engineering environment. The relevance and value of a transparent organization overview is described and derived. The Organization Architecture (OA) is explained as tool to achieve the required transparency of globally distributed roles and responsibilities. The relevance of the organization structure is distinguished from the process structure required for product quality (acc. Six Sigma) or process maturity (acc. SPICE). The method to introduce, maintain and use of the Organization Architecture is described, including the nomenclature for the organizational elements. The benefits of the OA along those phases are evaluated in an industry use-case. The typical organizational optimizations - identified by the OA - are introduced and explained. The limitations of the OA for optimization of engineering organizations are explained. The possible combination of the OA with other management methods for R&D are discussed.
Koark, Fabian Jorg UweKorandla, Arvind
Robust 1D Modelling for Automotive HVAC Warmup Prediction Using DFSS Approach2017-01-01793/28/2017
In an automotive air-conditioning (AC) system, the heater system plays a major role during winter condition to provide passenger comforts as well as to clear windshield defogging and defrost. In order to meet the customer satisfaction the heater system shall be tested physically in severe cold conditions to meet the objective performance in wind tunnel and also subjective performance in cold weather regions by conducting on road trials. This performance test is conducted in later stage of the program development, since the prototype or tooled up parts will not be available at initial program stage. The significance of conducting the virtual simulation is to predict the performance of the HVAC (Heating ventilating air-conditioning) system at early design stage. In this paper the development of 1D (One dimensional) model with floor duct systems and vehicle cabin model is studied to predict the performance. Analysis is carried out using commercial 1D simulation tool KULI®. All the simulation parameter which affects the correlation process has been studied carefully by using DFSS (Design for six sigma) methodology. L18 orthogonal array developed to understand the influence of each simulation parameters. Data analysis is carried out from DFSS study output and identified the importance of each simulation parameters which is being adjusted for correlation. This methodology helps to predicts accurately for any change in the HVAC heater systems circuit components like heater core, heater core inlet coolant flows, heater core inlet coolant temperatures, heater core airflow etc. This study enhances to reduce the number of physical tests, prototypes and cost involved in it.
Sambandan, SaravananValencia, ManuelS, Sathish Kumar
Optimization Solutions for Fan Shroud2016-01-13934/5/2016
Fan shroud is one of the critical components in an engine cooling system. It helps in achieving optimum air flow across the heat exchangers. The major challenge is to design a fan shroud which meets noise, vibration and harshness (NVH) requirements without compromising on air flow targets [1]. An improperly designed fan shroud will cause detrimental effects such as undesirable noise and vibration, which will further damage the surrounding components. In current days, multiple simulations and test iterations are carried out in order to optimize its design. The objective of this paper is to provide a design framework to achieve optimized fan shroud that meets NVH requirements in quick turnaround time using Design for Six Sigma (DFSS) approach [2]. The purpose of the Engine cooling system is to maintain the coolant temperature across the vehicle. Fan shroud accommodates the fan which in turn provides necessary air distribution across the radiator in order to have effective engine cooling. In this paper, DFSS approach is adopted to identify and optimize the factors which govern the NVH design of fan shroud. DFSS approach - nominal the best is used for this analysis which has an output, control factors and the noise factors. The modal frequency of the fan shroud is the output from the analysis and is evaluated in two modes, flexible mode and pumping mode. All the design parameters such as wall thickness, number of ribs, structural embossing which affects the output are considered as control factors. The under hood air temperature and the reduction in structural rigidity due to aging are considered as the noise factors. L18 Orthogonal experiment is used for this analysis, 18 design models are created in order to capture different combinations of control factor levels. Multiple control factors are examined to find out which would actually controls the designing of fan shroud in NVH perspective .Structural embossing and number of ribs for fan support are found to be the important design factors which contribute to better shroud NVH characteristics. A CFD simulation is also carried to check the airflow rate of the optimized design. The optimized design suggested in this paper had met both NVH and CFD targets. This study can be used further in order to reduce weight of the shroud and as best practice guidelines for future vehicles fan shroud designing which would ultimately reduce development time and cost.
Konikineni, PrabhakarSundaram, V.Sathish, KumarThirukkotti, Sankarasubramanian
Adapting Design for Six Sigma (DFSS) Methodology for Diesel Lean NOx Trap (LNT) Catalyst Screening2016-01-09534/5/2016
In order to meet LEV III, EURO 6C and Beijing 6 emission levels, Original Equipment Manufacturers (OEMs) can potentially implement unique aftertreatment systems solutions which meet the varying legislated requirements. The availability of various washcoat substrates and PGM loading and ratio options, make selection of an optimum catalyst system challenging, time consuming and costly. Design for Six Sigma (DFSS) methodologies have been used in industry since the 1990s. One of the earliest applications was at Motorola where the methodology was applied to the design and production of a paging device which Consumer Reports called “virtually defect-proof”.[1] Since then, the methodology has evolved to not only encapsulate complicated “Variation Optimization” but also “Design Optimization” where multiple factors are in play. In this study, attempts are made to adapt the DFSS concept and methodology to identify and optimize a catalyst for diesel applications. Lean NOx Trap (LNT) was selected as the catalyst of choice as it could become a development choice in future aftertreatment architecture for above-mentioned emission levels and cold start improvements. Catalysts from multiple washcoat manufacturers’ current production were acquired. Factors such as washcoat type, PGM loading, ratio and component aging were investigated. Catalyst performance was optimized under a specific set of testing conditions. The study proved that the DFSS methodology is a powerful tool that can be adapted for screening large number of catalysts in a relatively short period of time with reduced number of tests, under identical conditions with promising results.
Ahari, HomayounSmith, MichaelZammit, MichaelWalker, Brad
Directional Mahalanobis Distance and Parameter Sensitivities2016-01-02894/5/2016
Mahalanobis Distance (MD) is gaining momentum in many fields where classification, statistical pattern recognition, and forecasting are primary focus. It is a multivariate method and considers correlation relationships among parameters for computing generalized distance measure to separate groups or populations. MD is a useful statistic in multivariate analysis to test that an observed random sample is from a multivariate normal distribution. This capability alone enables engineers to determine if an observed sample is an outlier (defect) that falls outside the constructed (good) multivariate normal distribution. In Mahalanobis-Taguchi System (MTS), MD is suitably scaled and used as a measure of severity in abnormality assessment. It is obvious that computed MD depends on values of parameters observed on a random sample. All parameters may not equally impact MD. MD could be highly sensitive with respect to some parameters and less sensitive to some other parameters. Knowledge of parameter sensitivities help develop variation control plan in manufacturing so all produced parts belong to the good normal distribution and the scrap (waste) is eliminated. In this paper, the author has developed a formulation to calculate parameter sensitivities in terms of Eigenvalues and Eigenvectors of the characteristic (A-1) matrix where A is the correlation matrix of parameters. The formulation is further extended to develop Directional Mahalanobis Distance (DMD) where MD is measured in a desired direction to assess goodness of a random sample. This feature of the DMD method enhances discrimination power and has a huge potential for continuous monitoring of patient health or online product quality. Usefulness of this formulation is illustrated with an example.
Chinta, Balakrishna
SCALE Optical Hole Probe - The Next Step to Save Time and Cost in Auto Fastening with the Help of Optical Measurement Technology2015-01-26189/15/2015
SCALE is a modular, non-contact, in-line measurement system. It measures the diameter of the countersink directly after the drilling, the amount and distribution of sealant in the open hole, and the head height of the fastener as well as pressed out sealant (cf. Figure 1). The system is fast and reliable and the out coming information is reliable and trustworthy. Until now the system could not measure the inner diameter of the hole. The reason for this is that it is not possible to detect the inner diameter with a camera that looks only at the top of the component. But as our customers make the request to us, we decided to develop an optical hole probe system which is fully integrated in the auto fastening process. We think that a mechanical system cannot fulfill the customer expectations in terms of reliability, low maintenance, precision and speed. Only a non-contact system can measure permanently safe and fast the inner diameter of holes. The development objective was to create a system that is capable of to measure one inner diameter in less than 200 milliseconds with the precision better than 10 microns (0.0004 inch) at six sigma confidence level. The paper starts with a short description of different non-contact sensor types that are available on the market and that can be used to measure the inner diameter of a drilled hole in an auto fastening machine. The main part of the paper reports the results of our intensive investigation regarding the applicability for fast and non-contact optical measurement of the inner wall of the drilled hole. We have done more than 30.000 measurements in carbon fiber and metal.
Wolf, Bernd-MichaelMeiners, Christian
Automobile Powertrain Sound Quality Development Using a Design for Six Sigma (DFSS) Approach2015-01-23366/15/2015
Automotive companies are studying to add extra value in their vehicles by enhancing powertrain sound quality. The objective is to create a brand sound that is unique and preferred by their customers since quietness is not always the most desired characteristic, especially for high-performance products. This paper describes the process of developing a brand powertrain sound for a high-performance vehicle using the DFSS methodology. Initially the customer's preferred sound was identified and analyzed. This was achieved by subjective evaluations through voice-of-customer clinics using vehicles of similar specifications. Objective data were acquired during several driving conditions. In order for the design process to be effective, it is very important to understand the relationship between subjective results and physical quantities of sound. Several sound quality metrics were calculated during the data analysis process. A House of Quality (HOQ) matrix was created to characterize this correlation using the new metrics. Multiple sample candidate sounds were designed using sound design and simulation tools. A unique and preferred target sound was identified after an extensive double-elimination round of paired-comparison analysis of candidate sounds using an in-vehicle audio system. Final optimization was executed, with live jury, to demonstrate and verify the new unique and preferred sound.
Arvanitis, AnastasiosOrzechowski, JeffTousignant, ToddGovindswamy, Kiran
Optimization of MAC Side Window Demister Outlet by Parametric Modelling through DFSS Approach2015-01-03634/14/2015
In recent years clearing the mist on side windows is one of the main criterions for all OEMs for providing comfort level to the person while driving. Visibility through the side windows will be poor when the mist is not cleared to the desired level. “Windows fog up excessively/don't clear quickly” is one of the JD Power question to assess the customer satisfaction related to HVAC performance. In a Mobile Air Conditioning System, HVAC demister duct and outlet plays an important role for removing the mist formation on vehicle side window. Normally demister duct and outlet design is evaluated by the target airflow and velocity achieved at driver and passenger side window. The methodology for optimizing the demister outlet located at side door trim has been discussed. Detailed studies are carried out for creating a parametric modeling and optimization of demister outlet design for meeting the target velocity. In this methodology, a parametric modeling of demister outlet design using the factors such as length, width, vane angles and demister outlet to window angle is created using CATIA. Design for six sigma methodologies is followed for robust optimization and arrive at the combination of appropriate design factors which influences the velocity at side windows. L18 orthogonal design array matrix has been created and flow simulations are carried out using the commercial CFD software STAR CCM+. The impacts of each design factors and levels on the side window velocity have been analyzed extensively and best combination of design factors have been found out. Parametric modelling of demister outlet significantly aids in reducing the manual design time for simulation by 50% and DFSS approach helps in finding out the optimized design factors of demist outlet during the design phase of new programs.
Balashunmuganathan, VasanthNukala, RamakrishnaSampath Kumar, SathishkumarGovindarajalu, Murali
Creating a Two Sided Customer Loss Function2015-01-13574/14/2015
In the area of Human Factors and Usability research a desired output of many studies is identification of what value a specific Design Parameter should be set at to minimize customer dissatisfaction. A Customer Loss Function is a simple way to graphically display the probability customers will be dissatisfied at different levels of a given design parameter, due to a given failure mode. Many design parameters however, have two distinct but related Failure Modes (customer disatisfiers), typically representing two ends of the parameter (i.e. too much/too little; too hot/too cold; too fast/too slow). Each of these Failure modes is represented by its own unique Customer Loss Function. This paper will introduce a technique to combine these two One-Sided Loss Functions into a comprehensive Two Sided Loss Function. The mathematics behind the creation of both one sided and two sided loss functions is based on Binary Logistic Regression [1,2,3] Analysis Techniques. The benefits of incorporating both failure modes into one two-sided customer loss function include: 1) Being able to graphically display the Combined Customer Loss Function curve and utilize this visual aid to identify the level which minimizes customer dissatisfaction. 2) A secondary benefit is the ability to use the two-sided loss functions equation to develop an optimization tool for mathematically determining the minimum customer loss point. This is particularly useful if running a limit study (as opposed to a study with set levels).
Crowley, James A.
Advanced System Testing Incorporating Math-based, Attack-based, and Model-based Techniques Supported by the New Test Standards of the World2014-01-21489/16/2014
System testing can, in part, be defined as the application of concepts as an attempt to demonstrate that the implementation does not meet its intended use. Unfortunately, some industry verification test efforts only show that a system meets requirements which while necessary, are not sufficient to fully address a product's system-software testing. Managers, engineers, and testers may not be familiar with the wide variety of test concepts, approaches, and standards available for system-software testing-many of which can save projects money and effort in the long run. Newer software test standards and advanced techniques can offer a wealth of knowledge and improvement opportunities for software products. This paper offers a review of emerging software test concepts and standards in which teams will find potential value toward their improvement efforts including: Math-based techniques which apply combinatorial, statistical, Design of Experiments (DOE), or domain-based concepts Attack-based testing which focuses on common industry error taxonomies Independent model-based testing using tools and standards New standards-driven testing to address verification and validation (V&V), testing, and documentation. This paper reviews these recent developments in system-software testing concepts with sufficient references to allow readers to find the details of these extensive subjects when actually undertaking improvement efforts.
Hagar, Jon
Five Strategies for Improving Aerospace Supply Chain Quality Management and Performance2014-01-22319/16/2014
Aerospace suppliers face the daunting task of constantly improving time-to-market, reducing cost of quality and turning compliance into a competitive advantage. Managing to these constraints while staying profitable is a challenge faced by the entire aerospace supply chain face today. The intent of this presentation is to share five lessons learned on how aerospace suppliers can optimize for these three constraints while growing their businesses. The first is electronically enabling traceability both within a multi-tier supply chains and throughout suppliers. Automating traceability at the shop floor improves quality management and accelerates compliance. Specific methodologies and metrics used to accomplish this will be provided. Second, lessons learned from implementing Manufacturing Execution Systems (MES) showing how shop floor visibility has a direct effect on supplier performance is illustrated with case studies and metrics. Third, lessons learned in making compliance pay by benchmarking performance to AS9100C, ISO9001, and ITAR standards is provided. Fourth, integrating engineering, program management, project management office, accounting and finance workflows together provides exceptional insight into the value of a project in real-time. Examples and metrics of performance will be provided illustrating this point as well. The final lesson learned is that having a single, unified system of record across a diverse aerospace supply chain leads to greater gains in collaboration and communication, leading to proven profitability gains.
Columbus, Louis
Optimization of TOC Plumbing Line Pressure Drop using 1D Modeling2014-01-06604/1/2014
The performance of the Transmission Oil Cooler (TOC) is influenced significantly by the TOC plumbing lines which transmit the oil from transmission system to the oil cooler and back. Designing the optimum TOC plumbing line with lesser pressure drop is the need of the hour considering the complex nature of the vehicle packaging. Reducing the pressure drop increases the oil flow rate through the transmission which results in optimum performance. Improved transmission efficiency in turn shall improve the engine efficiency and performance. The improvements obtained from increased transmission and engine efficiency shall result in an overall increase in vehicle fuel economy. Optimization solutions are required in the early product development cycle where the components are not readily available and/or are prohibitively expensive to do testing. In such scenarios, one-dimensional (1D) simulations shall be employed to compute the pressure drop for faster and economical solutions. In this paper, the approach of creating a modeling tool for TOC plumbing line pressure drop is discussed. Design for six sigma (DFSS) methodology is followed to optimize the modeling tool. An L18 orthogonal array of iterations are created and 1D simulation is carried out using the commercial software Flowmaster® from Mentor Graphics Corporation. Samples are manufactured and tested in the system calorimeter to validate the simulation results. The frictional coefficients of the simulation model are fine tuned to match with the test data at all operating conditions. This fine-tuned model shall be used to predict the TOC plumbing line pressure drop for the future programs with good accuracy.
Sundaram, V.Arthanari, TharunnarayananS, Sathish Kumar
Prediction of Life Distribution and Design Robustness of Converter Joint Durability Using CAE Techniques2014-01-09164/1/2014
A variety of parameters influence the durability of a converter to pipe joint of an automotive exhaust system. Some of the parameters are design variables and some factors are related to manufacturing. The design parameters include the thickness of the components, diameter of the pipe, sleeve length of the cone etc. While the variables like the weld penetration and the fit-up of the joint are related to manufacturing. Traditional durability simulations utilizing computer aided engineering (CAE) methods are conducted using nominal values of the design and manufacturing variables. In reality scatter and randomness in parameters are present due to the tolerance in components and limitations of the manufacturing process. In this paper a CAE based stochastic approach to determine the life distribution for a converter joint of an automotive exhaust system is presented. During the first step of the study, design of experiments (DOE) using finite element analysis (FEA) were conducted to identify the critical parameters and interactions. Results from the DOE study were utilized to generate the response surface model to predict the durability of the joint. Finally, the response surface model was used to conduct Monte Carlo simulation and six sigma analysis to understand the robustness and reliability of the design. Correlation between the life of the converter joint predicted from this approach and life distribution obtained from physical tests are also presented. The main advantage of this approach is that the joint life is predicted using probabilistic distributions instead of the mean life.
George, JohnJoshi, BharatShih, H.R.Chen, Yin
Implementation of Lean Transactional in Tenneco's Ride Performance Europe Division - Review after Three Years of Implementation2014-01-07694/1/2014
After having successfully implemented Lean in Tenneco's Clean Air division, Tenneco Europe decided to expand Lean to its other divisions - Ride Performance including Aftermarket in 2011. These divisions were able to fully benefit from the best practices developed over the last 10 years. The implementation was articulated around two major axes: the execution of complex projects related to processes including several functions and sites. This approach allowed us to reach a critical mass in a reasonable time within the different functions and sites; the execution of smaller projects focused on one specific function,e.g.: Engineering or Sales. This approach is complementary to the first one since it enhances the spread of the lean spirit within the organization. This paper focuses on Tenneco's Ride Performance division and is split into two parts. Part 1 explains: the different steps required to implement the lean mindset; the challenges to implement it, i.e: the continuous improvement cycle, the enabling bureaucracy, the way of spreading the lean within an organization, the balance of top down and bottom up, the methodologies and ways of converting the benefits into concrete results. Part 2 illustrates: the two types of lean projects, i.e: the cross functional, multi-site ones and the small, so-called change agent projects that are more specific to a team or department. The first group of projects includes an example of the complex processes to prepare, build, pack and invoice a prototype. This involves all the key functions of an organization. The different steps of the workshop are shown. For the second group of projects (small projects) an overview shows the benefits in terms of: the just-in-time information. Some standardized planning processes and tools were developed and validated to allow the engineering community to access and utilize testing resources anywhere in the world. These measures strengthen testing flexibility by sharing resources and prevent the testing facilities suffering from over- or under-workload; Built-in-quality. The standardizations of testing procedures, engineering skills, data bases, or labeling of prototype parts are some typical examples which lead to a drastic reduction in waste, like waiting, re-work, over-processing, inventory, movement and transport; Operational stability. Better alignment between engineering departments and the improvement of some key tools like Computer Aided Design (CAD) are critical factors to improve operational efficiency. An example illustrates how a change agent project is treated. Finally, three years of lean implementation are reviewed. The outcome is very encouraging: Significant reduction of the process lead times of 20% to 50%; Freed-up time (less effort) due to the elimination of waste; Redeployment of the freed-up time for high value added tasks; Improved quality, accuracy of reporting and higher operational efficiency. ‘Soft-side’ improvements have been met such as: Improved communication and alignment between departments; Better understanding of the contribution their work makes to the overall value stream; Improved cross-functional team building through activities during Lean training and workshops; More consistent problem-solving mindset (seeing waste, finding root causes, continuous improvement); Significant improvements in motivation and morale.
Garcia, PatrickPaparelli, Sandro
Robust Analytical Methodology for Hood Overslam Travel using a DFSS Approach2013-01-13884/8/2013
Developing a robust model that can simulate all real world conditions a vehicle can experience can be extremely difficult to predict. When working through the engineering process, Computer Aided Engineers (CAE) traditionally set modeling parameters and conditions to a nominal setting. This is done to simplify the models so that it avoided inputting too much tedious details into the system and wasting so much engineering time preparing the work. It was soon realized that this strategy did not capture all the possible conditions a hood on a vehicle could experience. There was a need to develop a formal approach and method to correlate an analysis model to real world conditions. The Design for Six Sigma (DFSS) process was utilized to develop robustness in the techniques used to accurately understand the vehicle environment. The DFSS process is normally used to design and develop robustness into physical parts. This project took a different approach by applying the techniques in a virtual setting to create a process that can continuously improve correlation [1, 2, 3]. This paper highlights the development of the robust modeling technique that was used to predict over travel for the hood assembly of a vehicle. The goal is to improve CAE prediction capability with high success rate and also to improve the CAE analysis correlation with the test data. The current capability requires physical hardware testing to validate the design. In each segment of the DFSS process, there was a new approach to incorporating the tool to work with CAE analysis. It was extremely difficult to integrate the individual steps of the DFSS tools into the virtual world of CAE analysis. The DFSS principles of energy thinking did not apply to a virtual model, so modifications to the approach were undertaken. There was an extensive review of the control factors affecting the hood slam process and how it is applicable to the CAE model. The study was able to isolate each individual programmed input that drives the results of the model. Then it further used these individual inputs as the main drivers of the Design of Experiments (DOE). The input drivers were compared to physical measurements to understand what element of the model is creating irregularities. The variables that were not consistent with the physical results were further studied, and then developed into an optimized input. Finally, the over travel analysis was run again with the new inputs to create a greater improved accuracy level. The slam modeling technique will assist the CAE engineer to understand each individual input including striker loads, bumper loads, and seal loads, forces acting at the head lamps, grille and fascia. This will give the CAE engineer proper inputs to accurately predict the over travel of the hood, and protect General Motors from making costly last minute changes to design.
Nallapati, Sankar RaoMiller, JasonChinta, BalakrishnaMorley, John
A Statistical Approach for Correlation/Validation of Hot-Soak Terminal Temperature of a Vehicle Cabin CFD Model2013-01-08544/8/2013
A Design for Six Sigma (DFSS) statistical approach is presented in this report to correlate a CFD cabin model with test results. The target is the volume-averaged hot-soak terminal temperature. The objective is to develop an effective correlation process for a simplified CFD cabin model so it can be used in practical design process. It is, however, not the objective in this report to develop the most accurate CFD cabin model that would be too expensive computationally at present to be used in routine design analysis. A 3-D CFD model of a vehicle cabin is the central part of the computer modeling in the development of automotive HVAC systems. Hot-soak terminal temperature is a thermal phenomenon in the cabin of a parked vehicle under the Sun when the overall heat transfer reaches equilibrium. It is often part of the simulation of HVAC system operation. The strategy in our design process is to use a simplified CFD cabin model correlated with available test results for rapid routine design analysis. However, we have not seen published report to demonstrate a systematic correlation process for a cabin model where thermal physics are rather complex. This report introduces a DFSS statistical approach to develop an approximation (metamodel) of the expensive computer simulation of hot-soak process, and to guide the selection of input variable values subsequently to correlate the CFD model with given test data. The core process demonstrates using a small sample of CFD simulations to develop this approximation that enables model correlation with minimum computational effort. Although the targeted parameter for correlation in this study is the hot-soak terminal temperature, the procedure outlined herein is valid for other modeling results and other types of CFD models than the cabin model.
Ye, Tao
Critical Success Factors of Quality Culture Development in Automotive Industry2013-01-13304/8/2013
Purpose - This research aimed to investigate the process of quality culture development in automotive industry in in order to identify the critical success factors. Design/methodology/approach - A review of relevant literature is used to identify potential critical success factors for quality culture development. The research had targeted quality directors, quality managers, and quality employees, and consultants working in automotive industry. Data were collected with an electronic survey which included 20 close ended questions, each measured by using five-point scale, Out of total 150 questionnaire distributed, 60 useable responses were received resulting in 40% response rate. A judgmental sampling technique had been selected. Both descriptive and inferential statistics had been used to analyze this data. Findings - Our findings indicated that the belief among the respondents that management engagement, communication, training, teamwork among others are critical success factors for quality culture development in automotive industry. Also, the findings of the survey confirm that there is no significant difference among different experience levels, functions, and automotive sectors in perceiving and evaluating the critical success factors of quality culture development in automotive industry. Research limitations - The sample was limited to automotive industry and the results cannot be generalized too widely. However, this can be overcome by conducting other studies in different industries. Practical implications - Management and consultants working in automotive industry should focus on management commitment, communication, monitoring progress, and training to ensure successful implementation. Originality/value - This research identified the critical success factors quality culture development in automotive industry. Paper type - Research paper The authors Shady Baher El Safty is Quality Manager, General Motors
El Safty, Shady Baher
Integrated Virtual Approach for Optimization of Vehicle Sensitivity to Brake Torque Variation2013-01-05964/8/2013
Brake judder is a brake induced vibration that a vehicle driver experiences in the steering wheel or floor panel at highway speeds during vehicle deceleration. The primary cause of this disturbance phenomenon is the brake torque variation (BTV). Virtual CAE tools from both kinematics and compliance standpoints have been applied in analyzing sensitivities of the vehicle systems to BTV. This paper presents a recently developed analytical approach that identifies parameters of steering and suspension systems for achieving optimal settings that desensitize the vehicle response to BTV. The analytical steps of this integrated approach started with creating a lumped mass noise-vibration-harshness (NVH) control model and a separate multi-body dynamics (MBD) suspension model. Then, both models were linked to run in a sequence through optimization software so the results from the MBD model were used as quasi-static inputs to the lumped mass NVH model. Considering control factor parameters settings in the presence of noise factors, a case study revealed in this paper was conducted using Taguchi method for a Design for Six Sigma (DFSS) study. The benefit of this process is to design a robust system against BTV. This virtual optimization process can be implemented early during the vehicle design phase for performance target settings; it also provides tuning solutions for warranty reduction due to brake judder issues.
Zhang, BoBeyer, CharlesPelkey, JackWhitehead, GlennOpeiko, Alexandre
Critical Success Factors of Lean Manufacturing Implementation in Automotive Industry in China2012-01-05164/16/2012
Purpose - This research aimed to investigate the process of lean manufacturing implementation in automotive industry in China in order to identify the critical success factors. Design/methodology/approach - A review of relevant literature is used to identify potential critical success factors for lean manufacturing implementations. The research had targeted lean-manufacturing management, practitioners, process users, and consultants working in automotive industry in China. Data were collected with an electronic survey which included 20 close ended questions, each measured by using five-point scale, Out of total 200 questionnaire distributed, 80 useable responses were received resulting in 40 % response rate. A judgmental sampling technique had been selected. Both descriptive and inferential statistics had been used to analyze this data. Findings - Our findings indicated that the belief among the respondents that management engagement, communication, training, monitoring progress among others are critical success factors for lean manufacturing implementation in automotive industry in China. Also, the findings of the survey confirm that there is no significant difference among different experience levels, functions, and automotive sectors in perceiving and evaluating the critical success factors of lean manufacturing implementation in automotive industry in China. Research limitations - The sample was limited to automotive industry in China and the results cannot be generalized too widely. However, this can be overcome by conducting other studies in different countries or industries. Practical implications - Management and consultants working in automotive industry in China should focus on management commitment, communication, monitoring progress, and training to ensure successful implementation. Originality/value - This research identified the critical success factors lean manufacturing implementation in automotive industry in China.
El Safty, Shady Baher
Making Six Sigma a Cultural Norm2012-01-05134/16/2012
A common hurdle to enterprise-wide implementation of Six Sigma projects is the need to prepare employees so they are able to use statistical tools and graphical analysis techniques. Six Sigma deployment plans are replete with classes, seminars and coaching sessions aimed at the use and application of statistical procedures. Master Black Belts, Black Belts and external consultants are engaged in developing tutorial aids, analysis macros, and automated analysis routines so employees do not have to know too much to get the job done. A long term solution to this problem is to work with education providers and help them understand the industry's need for a better prepared work force. People who graduate from engineering, business and management programs need to be equipped with work-ready skills so they can make immediate contributions in the workplace. This paper and presentation describes the work two Six Sigma Master Black Belts have done to drive to the very root cause of this issue with their work targeting a fundamental cultural change. The paper describes four visits to a third grade classroom and the exercises and presentations conducted with the 8-10 year old students. Simple experiments were designed, executed and analyzed. The data were analyzed using arithmetic and graphical functions that the students had learned, making it a tangible demonstration that the concepts they are learning in school are the foundation of the analytical procedures used in the engineering offices and manufacturing facilities that is a part of their community. The activities focused on scientific methods and integrated the student's math, science, English composition, team building and presentation skills that were part of their regular curriculum. Special attention was given to strengthening self-confidence in mathematics and science, and the potential for a satisfying career in a field that incorporates this curriculum.
Miller, LisaFrimenko, Jacob
Critical Success Factors of Six-Sigma Implementation in Automotive Industry in Egypt2011-01-12704/12/2011
Purpose - This research aimed to investigate the process of six-sigma implementation in automotive industry in Egypt in order to identify the critical success factors. Research design and methodology - A review of relevant literature is used to identify potential critical success factors for six-sigma implementations. The research had targeted six-sigma management, practitioners, process users, and consultants working in automotive industry in Egypt. Data were collected with an electronic survey which included 20 close ended questions, each measured by using five-point scale, Out of total 600 questionnaire distributed, 240 useable responses were received resulting in 40 % response rate. A judgmental sampling technique had been selected. Both descriptive and inferential statistics had been used to analyze this data. Findings - Our findings indicated that the belief among the respondents that management engagement, communication, training, monitoring progress are critical success factors for six-sigma implementation in automotive industry in Egypt. Also, the findings of the survey confirm that there is no significant difference among different experience levels, functions, and automotive sectors in perceiving and evaluating the critical success factors of six- sigma implementation in automotive industry in Egypt. Research limitations - The sample was limited to automotive industry in Egypt and the results cannot be generalized too widely. However, this can be overcome by conducting other studies in different countries or industries. Practical implications - Management and consultants working in automotive industry in Egypt should focus on management commitment, communication, monitoring progress, training to ensure successful implementation. Value - This research identified the critical success factors of six-sigma implementation in automotive industry in Egypt
El Safty, Shady Baher
Innovative Robust Solutions for Lean Manufacturing in Automotive Assembly Processes2011-01-12544/12/2011
The article presents an innovative approach to the implementation of a robust design optimization solution in an automobiles assembly process. The approach of the entire project is specific to the 6 Sigma optimization process, by applying the DMAIC cycle integrated in a robust engineering approach for rendering lean the final product assembly process. According to the improvement cycle, the aspects specific for such a process are presented sequentially starting with the “Define” phase for presenting the encountered problem and continuing with the presentation of the scope of the project and its objectives. The “Improvement” cycle phase is applied by the analysis of the monitored 6 Sigma metrics (defined during the previous “Measure” phase and the cause and effect analysis, done during a brainstorming meeting developed during the “Analyze” phase). There follows a proposal for the innovative robust solution by which the assembly process is optimized. Therefore, we propose the final assembly of already painted doors on the already assembled cars with a special work-holding which is easy to handle by the human operator. The automation of designed and implemented solutions provides features of error proofing for the assembly process in the case in which the doors are not located accordingly on the work-holding locating elements, which may lead to various inconveniences during the assembly on the vehicle and/or some faults of the door quality, such as scratches or deformations because of the impacts. The initially presented process indices, for the not yet optimized process are finally evaluated after the implementation of the innovative solution for a comparative study of the initial monitoring results and after the implementation of the proposed corrective solution. This underlines the critical conclusions that are induced during the “Control” phase. The final conclusions point to the corrective / preventive actions for a sustainable and reliable optimization, which give the maximal process its overall efficiency.
Negrus, Andrei MihaiMihail, Laurentiu AurelChiru, Anghel
Quality Improvement Directly on the Production Floor2010-36-046610/6/2010
Over the past year, commercial vehicle manufacturers have already taken numerous measures to adapt to the economic turmoil, by laying off of temporary workers, reducing shifts and cutting back working hours among other steps. Soon, further-reaching measures may have to be taken to adjust to lower output levels. "The commercial vehicle industry is facing the prospect of having to make fundamental changes to its operations," according ACEA - European Automobile Manufacturers' Association (2009). Because of these facts the automobile world is each day more interested in Toyota industry development, while European and American automobile industry are in decadence, Toyota had accumulated profits every year during ten years until 2007. The Toyota wastes reducing methods, productivity and quality finished imposing his production administration system to the worldwide automobile industries. One big difference between occidental thinks' and Toyota production system, is that they works strongly inside people management, teaching the employees to solve small problems, avoiding in this way the big ones, increasing the final product quality. In this paper, will be presented a real case of quality improvement applied directly on production floor in an automobile Brazilian industry. The studied company manufactured this specific vehicle model in Brazil to be exported to Europe.
Baraldi, Emilio C.
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