Thesis (doctoral)--Uppsala University, 1990. / Includes bibliographical references (p. 146-153).

Thesis (doctoral)--Uppsala University, 1990. / Includes bibliographical references (p. 146-153).

Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: This report presents the application of the six sigma quality concept in solving a true business problem. Six sigma is a quality improvement and business strategy/tool developed by Motorola in the mid 1980s. It aims at delivering products and services that approach levels of near perfection. To achieve this objective a six sigma process must not produce more than 3.4 defects per million opportunities, meaning the process should be at least 99.9997% perfect [Berdebes, 2003]. Motorola's success with six sigma popularised the concept and it has now been adopted by many of the world's top compames e.g. General Electric, Allied Signal-Honeywell, etc. All the six sigma companies report big financial returns as a result of increased quality levels due to the reduction in the number of defects. 'General Electric reports annual benefits of over $2.5 billion across the organisation from six sigma' [Huag, 2003]. The six sigma concept follows a five step problem-solving methodology known as DMAIC (Define, Measure, Analyse, Improve, Control) to improve existing processes. Each of these steps makes use of a range of tools, which include quality, statistical, engineering, and business tools. This report first gives a theoretical presentation on quality and six sigma, attempting to answer the question 'What is six sigma'. A step-by-step guide on how to go through the DMAIC problem solving cycle is also presented. The six sigma concept was demonstrated by application to the colour removal process of a continuous processing plant manufacturing refined sugar. Colour removal is a very important process in sugar refining since the purpose of a refinery is to remove colour and other impurities from the raw sugar crystals. The colour removal process consists of three unit operations; liming, carbonation and sulphitation. Liming involves the addition of lime (calcium hydroxide) required for the formation of a calcium precipitate in the next unit operations. Carbonation is carried out in two stages; primary and secondary carbonation. Both stages involve the formation of a calcium carbonate precipitate, which traps colour bodies and other impurities. Sulphitation occurs in a single step and involve the formation of a calcium sulphite precipitate which also traps impurities. The pH and colour are the main variables that are being monitored throughout the colour removal process. Colour removal process Raw sugar Melting Carbonation Crystalli ~ Liming ~ c::J Secondary f+ Sulphitation .. Sugar sation Figure 1: Colour removal process The pH control of the two colour removal unit operations; carbonation and sulphitation, is very poor and as a result the colour removal achieved is below expectation. This compromises the final refined sugar quality since colour not removed in the colour removal processes ends up in the sugar. The first carbonation stage (primary) fails to lower the pH to the required specification and the second carbonation stage (secondary) is highly erratic, the pH fluctuating between too high and too low. The sulphitation process adds more sulphur dioxide than required and hence the pH is lowered below the lower specification limit. The six sigma DMAIC cycle was implemented in order to solve the problem of poor pH control. The Define phase defined the project and identified the process to be improved. The Measure phase measured the current performance of the process by collecting past laboratory data with the corresponding field instruments data. The data was used to draw frequency distribution plots that displayed the actual variation of the process relative to the natural variation of the process (specification width) and to calculate process capability indices. The Analyse phase analysed the data so as to determine the key sources of variation. The Improve phase used the findings of the analyse phase to propose solutions to improve the colour removal processes. The Control phase proposed a control plan so as to monitor and sustain the improvement gained. The key findings of the study are presented below: • Failure of the first carbonation stage to lower the pH to the required level is due to insufficient carbon dioxide gas supply. • The second carbonation reaction occurs very fast hence poor control will result in high variability. • The amount of colour removed is dependent on the input raw melt colour. • The histograms of the colour removal unit operations are off-centered and display a process variation greater than the specification width and hence a large proportion of the data falls outside the specification limits. • The % CaO and CO2 gas addition were found to be the key variables that control the processes centering on target. The % CaO having a stronger effect in the liming process and CO2 gas addition on the carbonation process. • The variation between the field instrument's pH and laboratory pH is the key variable that control the processes spread (standard deviation of the processes). • The processes Cpk values are less than C, (Cpk<Cp) meaning the processes can be improved by controlling the key variables that control centering (% CaO, CO2 gas addition). The processes capability indices are low, Cp<l meamng the processes are not statistically capable of meeting the required specifications at the current conditions. • Based on the findings of the study, the following deductions are made for the improvement of the colour removal processes in better meeting the required specifications. • Increase the CO2 gas supply to at least 4900 m31hr, calculated based on the fact that at least 140 rrr' gas is required per ton of solids in melt [Sugar Milling Research Institute Course Notes, 2002]. • Control the key variables identified to be the key sources of variation; % CaO, CO2 gas addition and variation between the field instrument's pH and laboratory pH. Reducing variation in the % CaO and increasing CO2 gas supply will improve the processes ability to maintain centering at the target specification. Maintaining a consistent correlation between the two pH readings; field instruments pH and laboratory pH will reduce the processes standard deviation and hence the processes spread. Reduction in the processes spread will minimize the total losses outside the specification limits. This will allow better control of the pH by getting rid of high fluctuations. • Control of the input raw melt colour is essential since it has an impact on the degree of decolourisation. The higher the input colour, the more work required in removing the colour. In improving the colour removal processes the starting point should be in ensunng process stability. Only once this is achieved, the above adjustments may be made to improve the processes capability. The processes capability will only improve to a certain extent since from the capability studies it is evident that the processes are not capable of meeting specifications. To provide better control and to ensure continuous improvement of the processes the following recommendations are made: • Statistical process control charts The colour removal processes are highly unstable, the use of control charts will help in detecting any out of control conditions. Once an out of control condition has been detected, necessary investigations may be made to determine the source of instability so as to remove its influence. Being able to monitor the processes for out of control situations will help in rectifying any problems before they affect the processes outputs. • Evaluation of capability indices- ISO 9000 internal audits Consider incorporating the assessment of the capability indices as part of the ISO 9000 internal audits so as to measure process improvement. It is good practice to set a target for Cp, the six sigma standard is Cp=2, this however does not mean the goal should be Cp=2 since this depends on the robustness of the process against variation. For instance the colour removal processes at the current operating conditions can never reach Cp=2. This however is not a constraint since for the colour removal processes to better meet pH specifications it is not critical that they achieve six sigma quality. A visible improvement may be seen in aiming for Cp=I. On studying the effects of CO2 gas addition the total data points outside specification limits reduced from 84 % to 33 % and by reducing the variation between field instruments pH and laboratory pH for the secondary pH the total data points out of specification reduced from 55 % to 48 %. These results indicate that by improving C, to be at least equal to one (Cp=l) the total data points outside specification can reduce significantly, indicating a high ability of the processes to meet specifications. Thus even if six sigma quality is not achieved, by focussing on process improvement using six sigma tools visible benefits can be achieved. / AFRIKAANSE OPSOMMING: Hierdie tesis kyk na die toepassing van die ses sigma kwaliteitskonsep om 'n praktiese probleem op te los. Ses sigma soos dit algemeen bekend staan is nie slegs 'n kwaliteitverbeteringstegniek nie maar ook 'n strategiese besigheidsbenadering wat in die middel 1980s deur Motorolla ontwikkel en bekend gestel is. Die doelstellings is om produkte en dienste perfek af te lewer. Om die doelwit te kan bereik poog die tegniek om die proses so te ontwerp dat daar nie meer as 3.4 defekte per miljoen mag wees nie - dit wil se die proses is 99,9997% perfek [Berdebes, 2003]. As gevolg van die sukses wat Motorolla met die konsep behaal het, het dit algemene bekendheid verwerf, en word dit intussen deur baie van die wereld se voorste maatskappy gebruik, o.a. General Electric, Allied Signal-Honeywell, ens. Al die maatskappye toon groot finansele voordele as gevolg van die vermindering in defekte wat teweeg gebring is. So by. beloop die jaarlikse voordele vir General Electric meer as $2.5 biljoen [Huag, 2003]. Die ses sigma konsep volg 'n vyf-stap probleem oplossings proses (in Engels bekend as DMAIC: Define, Measure, Analyse, Improve, Control), naamlik definieer, meet, analiseer, verbeter, en beheer om bestaande prosesse te verbeter. In elkeen van die stappe is daar spesifieke gereedskap oftegnieke wat aangewend kan word, soos by. kwaliteits-, statistiese--, ingenicurs-cn besigheids tegnieke. Die verslag begin met 'n teoretiese oorsig oor kwaliteit en die ses sigma proses, waardeur die vraag "wat is ses sigma" beantwoord word. Daama volg 'n gedetailleerde stap-virstap beskrywing van die DMAIC probleem oplossingsiklus. Die toepassing van die ses sigma konsep word dan gedoen aan die hand van 'n spesifieke proses in die kontinue suiker prosesserings aanleg, naamlik die kleurverwyderingsproses. Hierdie proses is baie belangrik omdat die doelstellings daarvan juis draai rondom die verwydering van nie net kleur nie maar ook alle ander vreemde bestanddele van die rou suiker kristalle. Die proses bestaan uit drie onafhanklike maar sekwensiele aktiwiteite waardeur verseker word dat die regte gehalte suiker uiteindelik verkry word. Tydens die eerste twee stappe is veral die pH-beheer onder verdenking, sodat die kleur verwydering nie die gewenste kwaliteit lewer nie. Dit bemvloed op sy beurt die gehalte van die finale produk, omdat die ongewenste kleur uiteindelik deel is van die suiker. Die pH inhoud is nie net nie laag genoeg nie, maar ook hoogs veranderlik - in beginsel dus buite beheer. Die DMAIC siklus is toegepas ten einde die pH beter te kan beheer. Tydens die definisiefase is die projek beskryf en die proses wat verbeter moet word identifiseer. In die meetfase IS die nodige data versamel om sodoende die inherente prosesveranderlikheid te bepaal. Die belangrikste bronne of veranderlikes wat bydra tot die prosesveranderlikheid is in die derde-- of analisefase bepaal. Hierdie bevindings is gebruik tydens die verbeteringsfase om voorstelle ter verbetering van die proses te maak. Die voorstelle is implementeer en in die laaste fase, naamlik die beheerfase, is 'n plan opgestel ten einde te verseker dat die proses deurentyd gemonitor word sodat die verbeterings volhoubaar bly. 'n Hele aantal veranderlikes wat elk bygedra het tot die prosesvariasie is identifiseer, en word in detail in die verslag beskryf. Gebaseer op die analise en bevindings van die ondersoek kon logiese aanbevelings gemaak word sodat die proses 'n groot verbetering in kleurverwydering getoon het. Die belangrikste bevinding was dat die huidige proses nie die vermoee het om 100% te voldoen aan die spesifikasies of vereistes nie. Die hoofdoel van die voorstelle is dus om te begin om die prosesveranderlikheid te minimeer of ten minste te stabiliseer - eers nadat die doel bereik is kan daar voortgegaan word om verbeteringe te implementeer wat die prosesvermoee aanspreek. Ten einde hierdie beheer te kan uitoefen en vanasie te verminder IS die volgende voorstelle gemaak: Statistiese beheer kaarte Die kleurverwyderingsproses is hoogs onstabiel. Met behulp van statistiese beheer kaarte is daar 'n vroegtydige waarskuwing van moontlike buite beheer situasies. Die proses kan dus ondersoek en aangepas word voordat die finale produkkwaliteit te swak word. • Evaluering van proses vermoee - ISO 9000 interne oudit Die assesering van die prosesvermoee behoort deel te word van die interne ISO oudit proses, om sodoende prosesverbeteringe gereeld en amptelik te meet. Die standaard gestel vir C, behoort gedurig aandag te kry - dit is nie goeie praktyk om bv. slegs 'n doelwit van C, = 2 soos voorgestel in ses sigma te gebruik nie, maar om dit aan te pas na gelang van die robuustheid van die proses wat bereik is. Daar is beduidende voordele bereik deur die toepassing van die DMAIC siklus. So het byvoorbeeld die persentasie datapunte buite spesifikasie verminder van 84% tot 33%, bloot deur te kyk na die effek wat die toevoeging van C02 gas tydens die proses het. Dit toon dus duidelik dat, alhoewel die proses huidiglik nie die vermoee het om te voldoen aan die vereistes van ses sigma nie, dit wel die moeite werd is om die beginsels en tegnieke toe te pas.

A técnica de PCR, utilizando-se \"primers\" desenhados a partir do gene que codifica uma proteína imunogênica de 31 KDa de Brucella abortus, foi empregada na detecção de Brucella spp. em 300 amostras de produtos lácteos clandestinos apreendidas em municípios dos Estados de São Paulo (SP) e de Minas Gerais (MG). Foram analisadas 49 amostras de queijo minas frescal e 18 de queijo meia-cura provenientes de MG, e 92 amostras de queijo minas frescal, 33 amostras de queijo meia-cura e 108 amostras de leite cru provenientes de SP. O isolamento bacteriano foi tomado como referência, porém não se isolou Brucella spp. de nenhuma das amostras cujos cultivos mostraram-se contaminados com outros gêneros bacterianos. Pela PCR foi observado que 37 amostras de queijo foram positivas: 29/141 (20,56 %) das amostras de queijo minas frescal e 8/51 (15,68%) das amostras de queijo meia-cura. Todas as amostras positivas na PCR para Brucella spp. foram confirmadas como sendo da espécie Brucella abortus pela técnica de PCR utilizando-se \"primers\" espécie-específicos. Foi instituída a reação de hemi-nested PCR para a diferenciação da cepa em B19 ou campo tomando-se como base a deleção genética de 702 pb existente na cepa vacinal B19. A padronização da técnica permitiu que todas as cepas de Brucella spp. fossem diferenciadas, revelando que 30 (81,08%) amostras eram B19 e 7 (18,92%) eram cepas de Brucella abortus de campo. A concordância estimada entre as técnicas de PCR e do cultivo microbiológico através do indicador Kappa foi considerada baixa (K = 0) devido ao não isolamento do microrganismo. / A PCR assay using primers designed based on the gene that encodes a 31 KDa immunogenic protein from Brucella abortus was used in the detection of Brucella spp. in 300 samples of illegal dairy products obtained in cities of the states of São Paulo (SP) and Minas Gerais (MG), Brazil. A total of 49 samples of minas frescal cheese and 18 samples of meia-cura cheese from MG were analyzed, besides 92 samples of minas frescal cheese, 33 samples of meia-cura cheese and 108 samples of raw milk from SP. Although bacterial isolation was used as reference, Brucella spp. was not isolated from any samples in which culture was contaminated by other genera of bacteria. PCR showed that 37 samples were positive for Brucella spp.: 29/141 (20,56 %) of the minas frescal cheese samples and 8/51 (15,68%) of the meia-cura cheese samples. All positive samples for Brucella spp. were confirmed as Brucella abortus by PCR using species-specific primers. Hemi-nested PCR was used for the differentiation between B19 and field strains, based on the genetic deletion of 702 pb in the vaccinal strain. Standardization of the technique enabled the differentiation of all Brucella spp. strains, showing that 30 of them (81,08%) were B19 and 7 (18,92%) of them were Brucella abortus field strains. Estimated agreement between PCR and microbiological culture as determined by Kappa indicator was considered to be poor (K = 0) due to the absence of isolation of the microorganism.

Orientador: Andre Tosi Furtado / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-04T03:06:11Z (GMT). No. of bitstreams: 1 Mariotoni_MariliArruda_M.pdf: 8967749 bytes, checksum: 28c0c42d34639803a8e56bc9178bf281 (MD5) Previous issue date: 2004 / Resumo: Este trabalho apresenta o desenvolvimento tecnológico das usinas de açúcar e álcool do Estado de São Paulo. Primeiramente, faz-se uma abordagem dos fatores mais gerais que explicam a formação, expansão e consolidação da agroindústria canavieira no Estado de São Paulo. Assim, busca-se atingir o objetivo de discutir a modernização tecnológica das usinas paulistas em relação aos principais centros produtores internacionais, principalmente visando os sistemas de preparo e extração de caldo de cana. No início da década de 1970, as usinas paulistas utilizavam uma tecnologia ultrapassada em relação aos outros produtores açucareiros do mercado internacional. Diante dessa situação, a Copersucar implementou um Programa de Modernização visando a elevar a produtividade das usinas paulistas para níveis internacionais definidos pelas usinas dos países que apresentavam tecnologias mais avançadas, principalmente África do Sul, Austrália e Havaí. Isso foi possível através de um programa pelo qual a Copersucar selecionou e implantou as tecnologias mais desenvolvidas e mais apropriadas ao parque sucroalcooleiro nacional. Os estudos realizados permitem concluir que o dinamismo do setor sucroalcooleiro, implementado pela Copersucar, possibilitou a consolidação dos objetivos do Programa de Modernização das usinas de açúcar e álcool no Estado de São Paulo. Isso ocorreu devido à superação dos gargalos tecnológicos com o desenvolvimento de novas tecnologias, o que propiciou uma elevação dos níveis de produtividade das usinas paulistas aos patamares das usinas internacionais que utilizavam tecnologias mais desenvolvidas / Abstract: This work presents the technological development of the sugarcane and alcohol industrial sector in the State of Sao Paulo. It is emphasized the most important points of the technological modernization of the plants regarding the main international producers centers. The sugarcane businessman from the State Sao Paulo realized that if they did not improved the quality of the product and they continued to produce sugar with an outdated technology, they would be eliminated of the world market. Ahead of this situation, Copersucar - The Brazilian Sugarcane Research Institute implemented a Modemization Prograrn aiming to elevate the productivity of the plants from Sao Paulo into international levels defined by the plants of the countries that introduced more advanced technologies, mostly Southern Africa, Australia and Hawaii. That was possible through a Program by which Copersucar selected and implanted the most developed and appropriated technologies to the Brazilian sugarcane industrial park. The studies done allow us to the conclusion that the dynamic of the sugar cane industry, summed to the Copersucar efforts gave the consolidation of the Sugar Cane Industries Modernization Program at the State of Sao Paulo. That allowed to overcome the technologies limitations compared with the development of new technologies, what gave higher levels of productivity to the State of Sao Paulo sugar cane industries at a similar level of the international industry, which used more modems technologies / Mestrado / Planejamento de Sistemas Energeticos / Mestre em Planejamento de Sistemas Energéticos

Context. 3D visualisations are highly demanded in different industries such as virtual factories. However, the benefits that 3D representations can bring to this industry have not been fully explored, being most of the representations either photorealistic or presenting abstract visualisations. Objectives. This thesis explores and compares two prototypes that present a visualisation of the process state of a factory. The first prototype presents a generic interface in which primitive 3D shapes convey the information of the factory status. The second prototype is complemented with specific and iconic 3D models of the factory that help the users associating the conveyed information to the factory flow. The motivation behind this dissertation is that the type of generic interface presented can lead to more reusable interfaces in the future. Methods. For the creation and development of the prototypes, the user-centered design process was followed in which the designs are iterated with users of the factory. Based on the two prototypes, a usability evaluation is conducted to analyse the perceived usability and the usability performance. This is complemented with post-interviews with all the participants. The results are presented attending to the triangulation methodology to support the strength of the qualitative findings. Conclusions. The results show that both interfaces are perceived as highly usable. However, the 3D iconic interface seemed to help the users more in depicting a better mental model of the factory flow, helping the users to complete most of the tasks with faster times. / This thesis explores and compares two prototypes that present a visualisation of the process state of a factory. The first prototype presents a generic interface in which primitive 3D shapes convey the information of the factory status. The second prototype is complemented with specific and iconic 3D models of the factory that help the users associating the conveyed information to the factory flow. The motivation behind this dissertation is that the type of generic interface presented can lead to more reusable interfaces in the future.

This thesis examines how drug policy and enforcement affect drug manufacturers. The approach taken is a comparative institutional analysis of cannabis and methamphetamine production. I focus on the effects of prohibition, privacy, and clandestine markets on producer behavior for these two drugs and the unintended consequences that result. I demonstrate that cannabis and methamphetamine producers both face substantial transaction costs and that producers alter their behavior to manage these transaction costs. I conclude that cannabis producers can adopt indoor, small-scale operations to hide their activity, which are capable of yielding continuous, high-potency crops. Methamphetamine producers also adopt small-scale, decentralized strategies, but commodity control increases their exposure and leads to greater overall transaction costs during the manufacturing process.

La traduction locale permet un contrôle spatial de l'expression des gènes. Dans ce travail, j'ai participé à deux cribles de localisation d'ARNm concernant plus de 1000 transcrits. Le premier était un crible double ARNm/protéine qui utilisait une approche de BAComics pour co-détecter les ARNm et la protéine pour laquelle ils codent. Le second a été réalisé à l'aide d'une nouvelle approche smFISH à haut-débit et a analysé tous les ARNm codant pour des protéines centrosomales et des régulateurs mitotiques. Le premier crible a révélé des cas de traduction locale dans divers compartiments subcellulaires, et notamment au niveau des protrusions cytoplasmiques, des centrosomes, de l’appareil de Golgi, des endosomes et des pores nucléaires, ce qui n'avait jamais été décrit auparavant. De manière remarquable, la traduction du peptide naissant était nécessaire pour le transport de nombreux transcrits localisés. De plus, j'ai montré que plusieurs ARNm (tels que ASPM et DYNC1H1) sont traduits dans des structures dédiées appelées usines de traduction.Le deuxième crible a révélé 8 transcrits localisés et traduits au niveau des centrosomes. J'ai montré que la localisation de ces 8 transcrits est régulée par le cycle cellulaire et qu'elle nécessite également la traduction du polypeptide naissant. En utilisant le gène ASPM comme modèle, j'ai visualisé des ARNm et des polysomes uniques avec les systèmes MS2 et SunTag, respectivement. Cela a révélé un transport dirigé des polysomes ASPM vers les centrosomes au début de la mitose, lorsque cet ARNm commence à être localisé. Ces données fournissent des preuves fortes d'un mécanisme de ciblage co-traductionnel dépendant de moteurs moléculaires ainsi que de la protéine naissante. Cela va à l'encontre du dogme actuel selon lequel le transport d'ARNm est un processus basé sur l'ARN et agissant sur des molécules réprimées pour la traduction. En revanche, cela suggère que des mécanismes tels que celui utilisé par le SRP sont plus répandus qu'on ne le pensait auparavant. / Local translation allows a spatial control of gene expression. Here, I participated in two mRNA localization screens imaging more than 1000 transcripts in total: (i) the first was a dual mRNA/protein screen that used a BAComics approach to co-detect mRNAs and the protein they encode; (ii) the second was done using a new high-throughput smFISH approach to screen all genes that encode centrosomal proteins and mitotic regulators. The first screen revealed cases of local translation at various subcellular compartments including cytoplasmic protrusions, centrosomes, Golgi, endosomes and the nuclear pore, which was never described before. Remarkably, translation of the nascent peptide was required for the transport of many localized transcripts. In addition, I showed that several mRNAs (such as ASPM and DYNC1H1) are translated in dedicated structures called translation factories.The second screen revealed 8 transcripts that are localized and translated at the centrosome. I showed that the localization of these 8 transcripts is regulated by the cell cycle, and that it also requires translation of the nascent polypeptide. Using the endogenous ASPM gene as a model, I imaged single mRNAs and polysomes with the MS2 and SunTag systems, respectively. This revealed a directed transport of ASPM polysomes towards centrosomes at the onset of mitosis, when this mRNA starts localizing. These data provide definitive evidence for a co-translational targeting mechanism dependent on motors as well as the nascent protein. This argues against the current dogma that mRNA transport is an RNA-based process acting on translationally repressed molecules. Instead, it suggests that SRP-like mechanisms are more widespread than previously thought.

This thesis is focused on the labor conditions of garment industry in developing countries. The text is structured as a comparative case study that is concerned with the situation in Cambodia and Bangladesh. Case studies of these countries describe domestic garment industry, its general and specific problems and a rate of compliance with labor standards. The goal of the thesis is to determine whether international organizations have an influence on the improvement of labor conditions in developing countries and compare it with other relevant actors. In this particular case the attention is focused on the International Labor Organization which manages its supportive programs in both countries but in a different manner. A pilot ILO program focused on the private sector has started in Cambodia thirteen years ago while in Bangladesh ILO had managed to run traditional program focused on the public sector until the Rana Plaza tragedy. Moreover, in the case of Bangladesh is a characterization of change after the tragedy. The thesis examines innovative ILO program that focuses on the monitoring of the garment factories, its functioning and outcomes. It also examines the role of ILO and its orientation by a theory of institutional change: whether it is possible to restore efficacy of one of the oldest...

Plant layout procedures available today consider either the quantitative attribute or the qualitative attribute of the layout problem. These procedures are based on maximizing or minimizing one objective function. Some of the procedures that address the multi-attribute nature of the plant layout problem are based on assigning weights to objective functions and then solving the problem by heuristic methods. Exact methods guarantee optimal solution but are computationally intensive for large sized problems. Heuristic methods do not guarantee optimal solution, but are computationally less intensive and relatively faster than the exact methods. This thesis suggests a procedure for solving the multi-attribute plant layout problem. The procedure is based on formulating the plant layout problem as a Quadratic Assignment Problem. Solution to the formulation is achieved by solving it by a combination of exact and heuristic methods. This solution procedure gives better results than just the heuristic method and is not computationally intensive. A computer implementation of the proposed procedure is developed in "C" programming language. A detailed experimentation is conducted to study the performance of the proposed procedure as compared to a well known procedure called Blocplan. The layouts generated by the proposed procedure are found to be much better than those generated by Blocplan. In the literature there is no discussion on the criticality of a layout to the change in flow related input data. An analysis is performed to study the affect of change in flow related input data on the final layout and a measure is developed for determining the criticality of a given layout to the change in flow related input data for the case of equal size departments. / M.S.