A parameter design introduced by Taguchi provides a new quality control method which can reduce cost-effectively the product variation due to various uncontrollable noise factors such as product deterioration, manufacturing imperfections, and environmental factors under which a product is actually used. This experimental design technique identifies the optimal setting of the control factors which is least sensitive to the noise factors. Taguchi’s method utilizes orthogonal arrays which allow the investigation of main effects only, under the assumption that interaction effects are negligible. In this paper new techniques are developed to investigate two-factor interactions for 2^t and 3^t factorial parameter designs. The major objective is to be able to identify influential two-factor interactions and take those into account in properly assessing the optimal setting of the control factors. For 2^t factorial parameter designs, we develop some new designs for the control factors by using a partially balanced array. These designs are characterized by a small number of runs and some balancedness property of the variance-covariance matrix of the estimates of main effects and two-factor interactions. Methods of analyzing the new designs are also developed. For 3^t factorial parameter designs, a detection procedure consisting of two stages is developed by using a sequential method in order to reduce the number of runs needed to detect influential two-factor interactions. In this paper, an extension of the parameter design to several quality characteristics is also developed by devising suitable statistics to be analyzed, depending on whether a proper loss function can be specified or not. / Ph. D.

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The South African government like most governments around the world create public entities to perform functions on its behalf and achieve particular objectives ranging from facilitating investments, delivering services or providing goods and advice. These public entities receive annual funding either whole or in part from the national fiscus and report to parliament through their respective Ministries. In the 2005/6 financial year government funded Umalusi 7, 69 million rands through direct transfer payments from the Department of Education, excluding any indirect payments from other governmental structures. Many public entities, about three hundred and thirty odd or so in South Africa, were promulgated to ensure and improve service delivery to the nation. However, they were not intended to be seen as an extension of their reporting departments. This research work evaluates the effectiveness of Umalusi in the education regulatory system and seeks to find ways to improve public entity effectiveness using the South African Excellence Model (SAEM) as the base tool to measure organisational effectiveness. A brief conclusion to this study is that Umalusi as a public entity, is adequately meeting its intended purpose. This is confirmed through its annual reports having never received a qualified audit since its inception. This research triangulates the results of the South African Excellence Model, the Questionnaire to senior education officials and the Auditors' Reports to confirm that Umalusi is effective as a public entity in the South African regulatory system. / Busniness Management / M.Tech. (Busniness Administration)

Thesis (MBA)--Stellenbosch University, 2007. / ENGLISH ABSTRACT: Continuous improvement is a consensus theme used by many industries for improving product quality and service. In the last decade a new quality philosophy known as Six Sigma has become well established in many companies, e.g., Motorola, General Electric, Ford, Honda, Sony, Hitachi, Texas Instruments, American Express, etc. Some have suggested that the Six Sigma quality improvement philosophy is not only impacting the global business sector, but will also re-shape the discipline of statistics. The Six Sigma philosophy for improving product and service quality is based upon existing principles established by other well-recognised quality experts, (Le. Deming, Juran, and Ishikawa). The significant departure of the Six Sigma philosophy from existing quality philosophies is that it promotes a stronger emphasis on monitOring production yield and manufacturing costs associated with any quality improvement effort. The other significant contribution that Six Sigma makes to the quality movement is the detailed structure for continuous improvement and the step-by-step statistical methodology. The goal of any Six Sigma improvement effort is to obtain a long-term defect rate of only 3.4 defective parts per million manufactured. Lean and Six Sigma are recent developments in continuous improvement methodology that have been popularised by several high-profile companies. The success and complementary nature of these methodologies has led to their combination into a single methodology, commonly called Lean Six Sigma (LSS). Although there is considerable literature available and many implementations of LSS, very little published research addresses the practical experiences of companies that have implemented LSS. To formalise a Lean Six Sigma implementation strategy for MeG Industries the focus of this research was to answer the research question: "How and why are certain implementations of LSS successful or unsuccessful?" To answer this question, this research investigates the implementation processes of organisations by addressing the following investigative questions: .:. How has LSS been deployed and implemented in organisations? .:. What are barriers to LSS deployment and how are they overcome? .:. What are challenges experienced during a LSS implementation and how are they overcome? The investigative questions further focused the research question and identified several factors that appeared to significantly contribute to implementation success; these factors are: .:. Fusing business strategy with continuous improvement strategy .:. Leadership commitment and involvement in the deployment and implementation processes .:. The use of consultants that are proficient and experienced .:. A defined organisational model and infrastructure which links the continuous improvement efforts with the performance measurement system and senior leadership .:. Defined and standardised personnel selection criteria This research's purpose is to assist MeG Industries to structure a continuous improvement program that abates or eliminates the negative effects caused by deployment barriers and implementation challenges. / AFRIKAANSE OPSOMMING: Deurlopende verbetering is 'n eenstemminge tema gebruik deur menige nywerhede vir die verbetering van produkgehalte en diens. Gedurende die afgelope dekade is 'n nuwe kwaliteitsfilosofie, bekend as Six Sigma, goed gevestig in verskeie maatskappye, bv. Motorola, General Electric, Ford, Honda, Sony, Hitachi, Texas Instruments, American Express ens. Sommige het voorgestel dat die Six Sigma kwaliteit verbeteringfilosofie nie alleenlik impak maak op die globale besigheidsekor nie maar sal ook die disipline van statistiek herskep. Die Six Sigma filosofie vir die verbetering van produk en dienskwaliteit is gebasseer op bestaande beginsels gevestig deur welbekende kwaliteitdeskundiges (bv. Deming, Juran en Ishikawa). Die betekenisvolle afwyking van die Six Sigma filosofie vanaf die bestaande kwaliteitfilosofie is die bevordering van 'n sterk klem op die moniteering van produksieopbrengs en vervaardigingskostes verbind met enige kwaliteitverbeterings inspanning. Die ander betekenisvolle bydrae wat Six Sigma aan kwaliteitbeweging maak is die struktuur vir deurlopende verbetering en die stap vir stap statistiese metodiek. Die doel van enige Six Sigma verbeterings inspanning, is om 'n langtermyn defekgraad van net 3.4 defektiewe parte per miljoen vervaardig, te verkry. Lean en Six Sigma is onlangse ontwikkelings in deurlopende verbeteringsmetodiek, wat populer gemaak is deur verskeie hoe profiel maatskappye. Die sukses en komplimerende karakter van hierdie metodiekke het gelei tot die kombinasie van 'n enkel metodiek, algemeen bekend as Lean Six Sigma (LSS). Alhoewel daar aansienlike literatuur beskikbaar is, bestaan daar min gepubliseerde navorsingstukke wat die praktiese implementering van LSS deur maatskappye aanspreek. Om 'n Lean Six Sigma implementering strategie vir MCG Industries te formuleer is gefokus op navorsing wat die navorsingvraagstuk: Hoekom en waarom is sekere implementerings van LSS suksesvol of onsuksesvol?". Om hierdie vraag te beantwoord ondersoek die navorser die implementeringsprosesse van organisasies deur middel van die volgende navorsingvraagstukke: - Hoe is LSS ontplooi en geimplementeer in organisasies? - Wat is die hindernisse tot LSS ontplooiing en hoe word dit oorbrug? - Watter uitdagings word ondervind met die implementering van LSS en hoe word dit oorbrug? Die ondersoek bevraagteken verdere gefokusde navorsingvraagstukke en identifiseer verskeie faktore wat skynbaar 'n betekenisvolle bydrae lewer tot suksesvolle implementering; hierdie faktore is: -Samesmelting van besigheidstrategie met deurlopende verbeteringstrategie -Leierskapvertroue en betrokkenheid in die ontplooiing en implementerings prosesse -Die gebruik van bekwame en ervare konsultante -'n Gedefineerde organisasiemodel en infrastruktuur wat gekoppel word aan deurlopende verbeteringsinstelling deur middel van 'n prestasiemetingstelsel en senior leierskap -Bepaalde en gestandaardiseerde personeel seleksie kriteria. Die navorsing doel is om MCG Industries behulpsaam te wees met die struktuur van 'n deurlopende verbeteringsprogram wat vermindering of eliminasie van negatiewe uitwerkings, veroorsaak deur ontplooiings hindernisse en implementerings uitdagings.

published_or_final_version / Business Administration / Master / Master of Business Administration

Least cost formulations for surimi seafood were studied by linear programming (LP) and nonlinear programming (NLP). The effects of water and starches on functional properties of Alaska pollock and Pacific whiting surimi gels were investigated. Six starches (modified potato starch, potato starch, modified wheat starch, wheat starch, modified waxy corn starch, and corn starch) and their mixtures were used as ingredients. Mixture and extreme vertices design were used as experimental designs. Canonical models were applied to the optimization techniques. Blending different kinds of surimi showed linear trends for each functional property, so that LP was successfully employed to optimize surimi lots. Strong interactions were found between surimi and starch or in starch mixtures. Two optimum solutions, obtained from LP and NLP, were compared in this study. Corn starch and modified waxy corn starch greatly improved the functional properties. / Graduation date: 1997

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Date: September 2017, Johannesburg / The focus in this research investigation is to investigate the Process Parameter Optimisation in Laser Beam Forming (LBF) process using the 4.4 kW Nd: YAG laser system – Rofin DY 044 to form 200 x 50 x 3 mm3 mild steel - AISI 1008 samples. The laser power P, beam diameter B, scan velocity V, number of scans N, and cooling flow C were the five input parameters of interest in the investigation because of their influence in the final formed product. Taguchi Design of Experiment (DoE) was used for the selection and combination of input parameters for LBF process. The investigation was done experimentally and computationally. Laser Beam Forming (LBF) input parameters were categorised to three different levels, low (L), medium (M), and high (H) laser forming (LBF) parameters to evaluate parameters that yield maximum bending and better surface finish/quality. The conclusion drawn from LBF process is that samples which are LBFormed using low parameter settings had unnoticeable bending and good material surface finishing. On the other hand, samples LBFormed using medium parameters yielded visible bending and non-smooth surface finishing, while samples processed using high LBF parameters yielded maximum bending and more surface roughness than the other two process parameters. / MT2018

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 1996. / This research project is an investigation into the effectiveness of an inspect and rework system called dynamic section control which has the purpose of improving the assembly quality of the BMW-3 series manufacturing in the Rosslyn Plant just outside Pretoria in South Africa, The system was introduced into the assembly plant in February 1995 to improve the assembly quality of the vehicles as quickly as possible. The main motivation behind the need for this system was to bring the quality onto the same level as the German plants in order to become recognised in the international network of BMW's manufacturing plants along with the new manufacturing plant in the USA The origins of the dynamic section control system come from the Munich 3-series plant as well as being based on the principles of poka yoke, a quality philosophy devised by the quality expert from Toyota in Japan, Shigeo Shingo, Defects found on the assembly plant's line, identified by the quality auditor and information from the marketing department regarding warranty claims are entered onto a checklist which is used by reworkers in the plant to inspect and make good the defects that have been found. The checklist is updated on a weekly basis, hence its name: dynamic section control. Seven rework stations, in which the dynamic section control reworkers work, have been strategically positioned in the assembly plant which trims the painted bodies it receives from the paint shop, The effectiveness of the system has been measured by analysing the information from the daily audits as well as investigating the trend of vehicles If rving the assembly plant still requiring rework and repairs off-line. The analyses were divided into three distinct periods. The first being approximately 4 months before the introduction of :he dynamic section control system, and the second and third periods after the introduction of the system. The results show that the dynamic section control system have a positive influence in improving the assembly quality of the vehicles, especially reducing the number of recurring defects. The number of defects that have only occurred once in each of the periods has remained reasonably constant indicating that the system has no impact in reducing the random occurrence of "one-off" defects. Another significant finding was. the increase in the number of vehicles requiring Department of Mechanical Engineering, University of the Witwatersrand repair off-line, attributable to the assembly plant, after the vehicle has left the assembly line. This increase is probably the result of an increased quality awareness within the assembly plant, resulting in reworkers identifying an increasing number of defects for repair off-line. Other factors such as clearer identification of production goals, training and development of a proportion of the assembly plant's workers in the German plants lor three weeks, reorganizing of support. staff by installing "the right people in the right place" and reducing the number of model derivatives in the plant have also contributed to the enormous quality improvement achieved. Further development of the. dynamic section control system is recommended by installing a rework station within each team area, and including the actions of dynamic section control in the work content of that team. Currently, the system uses external workers which are not part of individual teams as the current sections overlap team areas. Finally, it is recommended that the work of the dynandc section control reworker be incorporated as a noma! function within the team and be rotated amongst the team members. / AC2017