Manufacturing Quality Function Deployment: Literature Review and Future Trends

A comprehensive review of the Quality Function Deployment (QFD) literature is made using extensive survey as a methodology. The most important results of the study are: (i) QFD modelling and applications are one-sided; prioritisation of technical attributes only maximise customer satisfaction without considering cost incurred (ii) we are still missing considerable knowledge about neural networks for predicting improvement measures in customer satisfaction (iii) further exploration of the subsequent phases (process planning and production planning) of QFD is needed (iv) more decision support systems are needed to automate QFD (v) feedbacks from customers are not accounted for in current studies

Quality function deployment analysis based on neural network and statistical results

QFD is a method of translating high-level objectives into concrete actions and metrics. It is one of the techniques that aims to fulfill the customers’ satisfaction at the very beginning, namely the product design phase. This study focuses on the development of general QFD for machine specification selection so that it later can be used for any kind of machine evaluation prior to purchasing the machines. A set of questionnaires was used as an instrument and was distributed to 223 respondents. NN models were generated and statistical methods were used to explain the relationship between attributes in this study. The findings from the experiments conducted exhibit that the significant correlations of QFD with customer voices help to explain the relationship between attributes. The study also indicates that NN forecasting model has been established with 12.30 percent misclassification error in determining the customer voices based on QFD versus 6.3 percent using regression. This indicates that the approach has the potential in explaining the relationship between QFD and the customers,as well as predicting the type of customer if QFD information is provided. Hence, the study reveals the type of machine and type of operation that are favourable to customer prior to acquiring the machines for their industrial usage

Quality Function Deployment: More Than a Design Tool

Purpose – This study investigates to what extent QFD can be used in quality improvement rather than design activities. Design/methodology/approach – A framework was developed for implementation of QFD as a quality improvement tool. A case study approach is used to test this framework, and quality issues were analyzed using the framework in a ceramic tile manufacturing company. Findings – The results showed considerable improvements in the critical quality characteristics identified and sales rates, demonstrating the potential of QFD to be used in assessing and prioritizing areas of improvement, and converting them into measurable process or product requirements. Research limitations/implications – One case study was completed. More studies would be beneficial to support current findings. Practical implications – This framework provides structured approach and guidelines for practitioners in adapting QFD for quality improvements in existing products or processes. Originality/value – This study proposes a new framework to use QFD in quality improvement activities, expanding its application areas. Moreover, the results of the literature study performed provide a valuable collection of practical QFD implementation examples. Keywords Quality function deployment (QFD), quality improvement, customer complaints, voice of customer (VOC), house of quality (HOQ)

Application of Quality Function Deployment (QFD) in Die Redesign to Lowering Rework of Stamping Parts

In this work, QFD was utilized in die redesign to solve burrs and incorrect dimension defects in the stamping part. Because of these defects, almost 87% of processed parts were reworked in one industrial case. Based on root cause analysis, the burrs and incorrect dimension de- fects resulted in the cam piercing, piercing, and separating on compound dies of the existing stamping process. Dies configuration is indicated as the cause of these defects. This study aims to decrease the defects. The work consists of problem identification, RCA, die planning using the House of Quality of QFD phase 1, die design using QFD phase 2, and fabrication and assembly using QFD phase 3. Finally, QFD phase 4 tests the design die with 1,000 tons load and 30 samples in regular production and then analyzes. The result shows that reworked parts decreased from 87% to 0%. It concluded that QFD can be applied effectively in this work

Optimization of the product design through Quality Function Deployment (QFD) and Analaytical Hierarchy Process (AHP): A case study in a ceramic washbasin

Thesis (Master)--Izmir Institute of Technology, Industrial Design, Izmir, 2009Includes bibliographical references (leaves: 67-79)Text in English; Abstract: Turkish and Englishx, 81 leavesQFD is a methodology, which establishes a relationship between product and customer, determines product.s sales ability and carry out it to a high level during the process.In this study, QFD methodology, which is used in several industries, was implemented in the sanitary production industry. In this purpose, the washbasin, which is called as .Potsink. produced by Vitra, was chosen and examined implementation ability of the methodology. The aim for this choice is that Potsink.s design is different from usual washbasin forms and because of this reason, some sales problems would be appeared also there are some ergonomical and functional problems was observed.In the first step, which is developed by the customer.s voice, Analytic Hierarchy Process AHP was used. The relationship, which is between product and customer.s requirements, is determined by Analytic Hierarchy Process AHP.After this step, with customer requirements and technical details, which is matched with, are put in the house of quality (HoQ). Fallowing this step, improvement ratio and sales points are taken place in the house. Finally calculate all items and evaluated

Proposal of a conceptual model to minimize QFD application difficulties

Este trabalho apresenta uma proposta de desenvolvimento de um modelo de aplicação do QFD, com o objetivo de diminuir as dificuldades do uso do método. Para desenvolver este modelo foram realizadas as seguintes atividades: análise da literatura buscando identificar as informações sobre o uso do QFD, análise dos resultados de um levantamento de campo e de revisão de dados de entrevistas em empresas que utilizaram o método e da aplicação do AD (Axiomatic Design) para desenvolver o modelo conceitual proposto com os dados das etapas anteriores. As principais dificuldades identificadas a serem resolvidas estão relacionadas à matriz da qualidade, ao trabalho em equipe, ao modelo conceitual (do próprio QFD) e à avaliação da aplicação do QFD. Os resultados indicam a viabilidade do uso do AD para atender a este objetivo, mas o trabalho conclui que uma validação empírica é necessária.This work presents a proposal of a conceptual model of QFD application aiming at minimizing the difficulties in the use of the method. To develop this model, the following stages were carried out: literature review to identify information about the QFD use, analysis of a field research and review of previous interview data from QFD users, and the use of AD (Axiomatic Design) to develop the suggested model with the data of previous stages. The main difficulties which were identified and yet to be solved are related to quality matrix, team work, QFD conceptual model and QFD application assessment. The results indicate the feasibility of the AD use to achieve this objective but the work concludes that an empirical application is needed for validity

A product design framework for one-of-a-kind production using integrated quality function deployment and operational research techniques

The process of product design as an early stage of new product development provides systematic approaches that can lead to the success of a company’s competitive strategy in the current turbulent market. By launching an efficient product design procedure can result in the reduction of engineering modifications, cost and production time. One-of-a-Kind Product (OKP) is known as a particular manufacturing system of new product design and development with emphasis on the special order concept. Quality Function Deployment (QFD) is a comprehensive design framework with cross-functional team members that leads to the development of new or improved products. QFD starts with the House of Quality (HOQ) as an organizing matrix to identify the customers’ requirements (CRs) and translate them into the technical attributes (TAs) of the product and followed by determining the target values for the sets of technical attributes. An evaluation approach to determine the relative importance of CRs and TAs should be considered. In previous researches, the traditional methods such as simple scoring method and application of operational research techniques such as Analytic Hierarchy Process (AHP) were reported to weigh the requirements and attributes. Despite the obvious inner-relationships among the elements, considering the HOQ as a hierarchical system may be inefficient. In addition, the contradictory effects of a TA on two or more CRs, is the problem that has been neglected. Here, a mathematical model was developed for calculating the TAs target values. A case study (dry gas filter, Namdaran Petro-Gas Industries (NPI™)) is presented to exhibit and verify the procedure of OKP product design. Initially, the framework was developed by integrating QFD-operational research (Analytic Network Process (ANP)) as a systematic method for improvement of dry gas filter design. Interview and study of documents were used to identify the CRs. A robust evaluation on customers’ priority and attributes’ importance with respect to inner-relationships among criteria/sub-criteria was performed. Furthermore, the effects of TAs on CRs with regard to their direction (positive/negative) were considered as the fundamental for developing a Multi-Objective Decision Model (MODM) to be used for determining the TAs target values. For this purpose, the fuzzy conversion scaling technique followed by formulating the partial satisfaction separately was applied. Modified TOPSIS was used to select the basic design among the available designs for further modification. Later, the process continues with the second phase, translating the TAs into the key parts. The available options (retailers) to supply the key parts were identified. As the normal procedure of QFD the relative importance’s of key parts and the options were determined. Finally, a zero-one goal programming was presented to select the optimum options for each key part subject to the budget constraint. Overall, the developed QFD-ANP framework provides a systematic approach that has the potential to be used for designing OKP product

Quality function deployment opportunities in product model supported design

This thesis describes the development of a QFD information model established in an environment where design information is shared between software applications. The main objectives of the research are to establish a QFD information structure within a Product Data Model and to demonstrate how this enables an intelligent, knowledgebased analysis of QFD information contained in a Product Model. The generic structure of the QFD information has been defined and implemented in prototype software and its value is demonstrated through experimentation in two case studies. Successful implementation of the case studies proved that the QFD information structure is able to capture QFD information as persistent objects residing in a Product Model. It also demonstrates that an intelligent knowledge-based QFD expert can be implemented alongside the QFD information model to accomplish useful, consistent, reasoned analysis of QFD information. The research has achieved its aim to provide a new contribution in the product design domain, and to the effectiveness of Concurrent Engineering activities, through better use of Quality Function Deployment

Automated Fibre Placement with In-Situ Ultraviolet Curing and On-The-Fly Resin Impregnation

Vehicle emissions contribute to up to one third of the world's air pollution [1]. Reducing vehicle weight is crucial to reducing these emissions. Composite materials offer high specific strength-to-weight ratios which make them ideal for lightweight applications; however, existing composite manufacturing is slow and expensive. Automated Fibre Placement (AFP) is a state-of-the-art composite manufacturing process but is limited by the low complexity of parts it can produce; the cost, size and speed of the actuation systems; expensive and sensitive material options; and numerous pre and post-processes required in order to complete a part. This research proposes a new and efficient composite manufacturing process that addresses these limitations by combining AFP technology with in-situ ultraviolet (UV) curing and on-the-fly fibre and resin impregnation (UVAFP). The body of this thesis focused on proving the process concept and building robust predictive models for the technology. It was proposed that reducing the size of the placement head would increase the capability of this technique to manufacture more complex parts. It was shown that by optimising the placement head clearance angle, placement head width and the compaction roller radius the minimum placement radius and arc length could be as small as 100mm and 90 degrees respectively. It was also demonstrated that industrial robots were sufficiently accurate and repeatable to act as placement articulators for AFP. The feed rate, path interpolation point filtering and spindle speed were optimised to achieve a path following accuracy of less than 0.042mm. By increasing the tension in the tow and compaction force, dry fibre tows were shown to be a suitably dimensionally stable replacement for expensive towpregs with minimal gaps and overlaps. Dry glass fibre tows and bulk vinylester resin impregnated on-the-fly was chosen as an inexpensive and versatile material system and consolidation approach for use in UVAFP. The material system was shown to have comparable mechanical properties to aluminium and steel but lighter with equivalent properties to composites manufactured by traditional techniques. Rapid impregnation times were demonstrated up to 2160 mm/sec. High intensity UV light curing eliminated the need for post process curing and shortened the cure time and increased layup speeds. When the UV light was applied in a ply-by-ply in-situ approach, the cure time was measured to decrease the current thermal cure cycle length by 43.75% and the degree-of-cure was increased by 1.3% (as measured indirectly by the interlaminar shear strength). By characterising the process parameters the effect on degree of cure and degradation could be controlled and predicted. A degree of cure in excess of 99% was achieved, providing equivalent material properties to traditional thermal cured composites while minimising peak exposure temperatures, thus reducing mass loss caused by thermo-oxidative degradation. UVAFP was demonstrated to be a viable composite manufacturing process capable of producing high quality components and addressing the limitations of current AFP systems. The technology was shown to address efficiency shortfalls and make composite manufacturing economical and accessible to vehicle manufacturers searching for manufacturing process solutions for lightweight