A system has been developed and is being used at H. M. -Ltd. for estimating the labour and overhead costs of components manufactured by a wide variety of production processes. The system uses multiple linear regression analysis to develop estimating equations that quantitatively measure the relationship between the production time of a component and the factors that influence this time. Production times can then be converted to cost using appropriate labour and overhead cost rates. The system uses design features only for predictor variables in the estimating equations. Hence designers with little concept of manufacturing methods can use the system to cost designs as they evolve. This feature therefore provides designers with a powerful cost optimization tool. The manufacturing time data used to develop estimating equations represents current operating conditions at Herbert Morris Ltd. Hence the estimated times can be used directly as standard times for the planning and control of manufacturing. In this way manufacturing costs will be directly linked to the design features of a product. Software has been developed to allow a computer to retrieve appropriate equations and compute the production times and costs of components. This software could form the basis for a larger system that also generates producibility data for designers. A method of allowing designers to estimate the development times for individual components and assemblies has been developed. This facility enables the design process to be scheduled such that the overall new product development time could be minimized. An important element of this scheduling method is the ability to allocate resources between components to be designed on the basis of relative cost and importance to. the overall success of the project.

Owners of infrastructure assets have responsibility for the management of a diverse portfolio of civil engineering assets. These assets make up the foundations of modern society and are arguably pivotal in the economic growth and wellbeing of a nation. It is of no surprise therefore, that asset management business practises have risen in popularity as the UK’s infrastructure asset base continues to grow and inevitably ages with time. In the context of water and waste water infrastructure assets, which communities rely upon for health, economy and environmental sustainability, it is widely acknowledged that these assets have historically suffered from underinvestment. Whilst funding shortfalls have been evidenced historically, through the inadequacy of infrastructure to meet the needs and challenges of the past, it is of great concern that infrastructure expenditure is reducing in real terms as a result of the global financial crisis. This is leading to a widening funding gap between the available and the required finances for infrastructure investment which is further compounded by natural phenomena and human behaviours, i.e., climate change, population growth and urbanisation. To further intensify the problem, asset planning and management in the water industry is considered a complex and challenging discipline because of high interdependencies and the vast quantity of assets themselves. In acknowledgement of this global position, this thesis seeks to address some of the key challenges faced by utility companies in the adoption of asset management best practice across water and waste water assets, namely: • Operational decision making - the efficient and effective specification of least-cost rehabilitation programmes from condition information that ensure behavioural alignment with an organisations strategic objectives. • Tactical decision making - achieving risk based asset level inspection prioritisation that considers serviceability performance, for two particularly challenging asset groups: i.) High value - low volume assets and ii). Low value - high volume buried infrastructure. • Strategic decision making - identifying optimal long-term investment plans and asset management policies for assets that have previously not benefited from such technological advancements. To improve upon operational decision making, the author capitalises on the availability of condition inspection information for buried sewerage infrastructure by applying advanced optimisation techniques to help form an environment where the decision makers is presented with an array of optimal rehabilitation solutions. The trade-off curve that is presented uniquely evaluates solutions for the benefits they offer in-terms of: condition improvement, cost and operational performance. A financially favourable comparison (up to 45% saving) is drawn between the optimisation results which are automatically generated by the model and those that have been developed manually by experienced engineers in a ‘real world’ case study. However, it could be argued that the greatest benefit arises from the trade curve of feasible solutions which are presented to the decision maker across a range of investment levels. In recognition that tactical and strategic decision making have been the focus of a substantial amount of research for commonly found infrastructure assets, i.e., public sewers and water mains, a focus has been placed on improving upon and adopting best practise across infrastructure assets which have not previously benefited from the technological developments across these decision making levels. Firstly, a methodology for translating standardised condition inspection information into more meaningful reliability scores, to support risk based planning and decision making, is presented for service reservoirs. A service reservoir can be regarded as high value- low volume infrastructure asset and would typically have its condition evaluated between 1 (poor) to 5 (good). A case study demonstrates how this new reliability scoring mechanism has been successfully applied during a typical structural condition survey. The output from this process is a fully document reliability assessment for each component of the service reservoir. The output can be aggregated to provide an overall reliability assessment for the structure and/or used to target specific remedial works to troublesome components. Secondly, two methodologies are presented which address the fact that high volume – low value infrastructure assets across both the water distribution and wastewater collection networks, are typically less well understood and often sub-optimally managed in comparison to more critical or higher value assets. 1. A methodology has been developed to help UK water companies overcome the recent legislative changes associated with Section105A of the Water Act; which has transferred ownership of the private sewer network to UK water companies. The new methodology which has been developed, has allowed one of the UK’s water and sewerage companies to initiate a proactive asset management programme with the aim of addressing the deteriorating condition of these assets whilst also tackling their associated serviceability performance. Initially, a number of GIS tools are used to provide an estimate of the likely extent of the transferred network before a well-established public sewer deterioration model is used to predict the condition and operational performance of these S105A assets over time. 2. A novel deterioration modelling framework is developed by coupling the latest geospatial technologies with statistical deterioration modelling techniques. The modelling framework is specifically applied to small diameter water distribution assets (25-50mm diameter), known as communication pipes, which connect individual properties to the water distribution mains. Reliability curves are developed from failure data provided by two UK based Water Companies that have captured specific communication pipe failure records since 2001. The deterioration modelling curves and supporting data are compared and contrasted to demonstrate the robustness of this modelling approach, which is shown to be capable of modelling failure rates to a high degree of accuracy. This was validated by comparing the predicted number of failures against three years of failure data not used during the model building process. The yearly failure counts were predicted to within +/-5% accuracy and the overall cumulative modelled failure count at the end of 2014 was predicted within 1%. To conclude, the successful deterioration modelling tools for communication pipes are explored further, via the development of a strategic whole life cost optimisation framework for these assets. The outputs from the previous geospatial mapping tool are used alongside the calibrated Weibull deterioration curves to drive a whole life cost and performance analysis. Against this improved understanding of whole life costs, an optimisation algorithm is used to evaluate the trade-off between whole life costs (totex) and the prevention of future asset failures (serviceability). The model successfully identifies optimised investment policies according to the decision maker’s priorities which is evidenced in a case study that shows outperformance against existing maintenance policies for these assets. Financial savings in the region of £8.5M, or the prevention of 1,320 asset failures, were shown to be possible over a 25 years planning horizon in the case study. For the avoidance of confusion, the term ‘integrated’ is considered from the perspective of the three decision making levels associated with the management of an asset, namely: strategic, tactical and operational decision making. Therefore, data quality improvements and the management of information transactions between decisional levels are inherently considered within all of the methodologies developed in this thesis.

Concerns about energy supply and climate change have been driving companies towards more sustainable manufacturing while they are looking on the economic side as well. One practicable task to achieve sustainability in manufacturing is choosing more sustainable technologies among available technologies. Combination of two functions of ‘Technology Selection’ and ‘Capacity Planning’ is not usually addressed in the research literature. The importance of integrated decisions on technology selection and capacity planning at such strategic level is therefore essentially important. This is supported by justifications in some selected manufacturing areas particularly concerning economies of the scale and accumulated knowledge. Furthermore, manufacturing firms are working in a global competitive environment that is changing in a continuous way. Strategic design of systems under such circumstances requires a carefully modelled approach to deal with the complexity of uncertainties. The overall project aims are to develop an integrated methodological approach to solving the combined ‘technology selection’ and ‘capacity planning’ problems in manufacturing sector. The approach will also incorporate the multi-perspective concept of sustainability, while taking uncertainties into account. A framework consisting of four modules is proposed. Problem structuring module adopts an Ontology method to map the technology mix combinations and to capture input data. ‘Optimisation for Sustainable Manufacturing’ module addresses the optimisation of technology selection and capacity planning decisions in an integrated way using Goal, Mixed Integer Programming method. The model developed takes the multi-criteria aspect of sustainability development into account. Three criteria, namely a) Environmental (e.g. Energy consumption and Emissions), b) Economics, and c) Technical (e.g. Quality) are involved. ‘Normalisation algorithm by comparison with the best value’ method is adopted in this research in order to facilitate a systematic comparison among various criteria. The economic evaluation is based on ‘Life-Cycle Analysis’ approach. The ‘Present Value (PV)’ method is adopted to address ‘Time Value of Money’, while taking both ‘Inflation’ and ‘Market Return’ into account in order to make the proposed model more realistic. A mathematical model to represent the total PV of each technology investment, including both capital and running costs, is developed. ‘Sensitivity Analysis’ module addresses the uncertainty element of the problem. A controlled set of re-optimisation runs, which is guided by a tool coded in Visual Basic for Applications (VBA), is developed to perform intensive sensitivity analyses. It is aimed to deal with the uncertainty element of the problem. Within ‘Solution Structuring’ module, two knowledge structuring schemes, namely Decision Tree and Interactive Slider Diagram, are proposed to deal with the large size of solution sets generated by the “Sensitivity Analysis” module. An innovative, hybrid, Supervised and Unsupervised Machine Learning algorithm is developed to generate a decision tree that aims to structure the solution set. The unsupervised learning stage is implemented using DBSCAN algorithm, while the supervised learning element adopts C4.5 algorithm. The methodological approach is tested and validated using an exemplar case study on coating processes in an automotive company. The case is characterised by three operations, twelve possible technology mix states, both capital budget and environmental limits, and 243 different sensitivity analysis experiments. The painting systems are evaluated and compared based on their quality, technology life-cycle costs, and their potential VOC (Volatile Organic Compounds) emissions into the air.

Thesis (MBA (Business Management))--Stellenbosch University, 2009. / ENGLISH ABSTRACT: A typical medium-sized service company in South Africa faces definite challenges and misses opportunities in optimising and managing its operational expenses in its sourcing and supply chain. Medium-sized companies generally do not have the benefit of sophisticated in-house procurement divisions and extensive buying power but they still have to optimise their expenses in order to ensure maximum profitability and business longevity. The study addresses these challenges and opportunities by developing and proposing a framework for a typical medium-sized service company that does not have a central procurement function related to the cost optimisation and management of the identified sourcing and supply-chain elements. The research process entails the development of a conceptual framework developed from literature analysis and a representational practical environment as well as the testing, reviewing and validating of the test implementation of the framework. The results flowing from the testing and implementation of the framework are excluded from the research project. The results are displayed in the form of a summary of specific relevant information around each framework element as well as a conceptual framework. Recommendations are made in relation to the implementation and practical adaptation of the framework. It is concluded that a medium-sized service company can successfully optimise and manage its costs in the sourcing and supply-chain elements in the absence of a central procurement function. This requires the effective implementation of the developed framework, which was adapted from sophisticated larger companies. Implementation and the measurement process need to be driven or, preferably, conducted by the medium-sized company owner or management. Buy-in of the framework and the processes around it needs to be obtained from employees, suppliers and other stakeholders. / AFRIKAANSE OPSOMMING: ’n Tipiese mediumgrootte diensverskaffingsonderneming in Suid-Afrika staar spesifieke uitdagings in die gesig en ontbeer geleenthede met betrekking tot die optimalisering en bestuur van die bedryfsuitgawes in sy aankoop- en verskaffingsketting. Mediumgrootte ondernemings beskik in die algemeen nie oor die voordeel van ’n gesofistikeerde interne aankoopafdeling en groot aankoopkrag nie, maar hierdie ondernemings moet nog steeds hulle koste-uitgawes optimaliseer in die nastreef van maksimale wins en besigheidsukses. Die navorsingstudie neem hierdie uitdagings en geleenthede onder die loep deur die ontwikkeling en aanbeveling van ’n raamwerk vir ’n tipiese mediumgrootte diensverskaffingsonderneming wat nie oor ’n sentrale interne aankoopafdeling beskik nie. Die raamwerk is gebaseer op koste-optimalisering en -bestuur van die geïdentifiseerde aankoop- en verskaffingskettingelemente. Die navorsingsproses behels die ontwikkeling van ’n konseptuele raamwerk deur literatuuranalise en ’n verteenwoordigende praktiese omgewing, sowel as die toetsing, hersiening en geldigverklaring van die raamwerk tydens die toets-implementering daarvan in die praktiese omgewing. Die resultate van die toets en implementering van die raamwerk vorm nie deel van hierdie studie nie. Die navorsingsresultate word ten toon gestel in die vorm van ’n opsomming van die relevante raamwerkelemente sowel as ’n ontwikkelde raamwerk. Aanbevelings ten opsigte van die implementering en praktiese aanpassing van die raamwerk word dan gemaak. Die gevolgtrekking word gemaak dat ’n mediumgrootte diensverskaffingsonderneming wel in die afwesigheid van ’n sentrale interne aankoopafdeling sy kostes in die aankoop- en verskaffingsketting suksesvol kan optimaliseer en bestuur. Dit kan gedoen word deur die doeltreffende implementering en aanwending van die ontwikkelde raamwerk wat vanaf groter ondernemings aangepas is. Die raamwerk se implementering- en metingsproses moet deur die eienaar of bestuur van die mediumgrootte onderneming gelei, of verkieslik uitgevoer, word. Die werknemers, verskaffers en ander belanghebbendes se ondersteuning vir die raamwerk en gepaardgaande prosesse is baie belangrik vir die implementering en sukses van die raamwerk.

Background. Shewhart was the first to describe the possibilities that come with having a statistically robust process in 1924. Since his discovery, the importance of a robust process became more apparent and together with the consequences of an unstable process. A firm with a manufacturing process that is out of statistical control tends to waste money, increase risks, and provide an uncertain quality to its customers. The framework of Statistical Quality Control has been developed since its founding, and today it is a well-established tool used in several industries with successful results. When it was first thought of, complicated calculations had to be performed and was performed manually. With digitalisation, the quality tools can be used in real-time, providing high-precision accuracy on the quality of the product. Despite this, not all firms nor industries have started using these tools as of today.    The costs that occur in relation to the quality, either as a consequence of maintaining good quality or that arises from poor quality, are called Cost of Quality. These are often displayed through one of several available cost models. In this thesis, we have created a cost model that was heavily inspired by the P-A-F model. Several earlier studies have shown noticeable results by using SPC, COQ or a combination of them both.     Objectives. The objective of this study is to determine if cost optimisation could be utilised through SQC implementation. The cost optimisation is a consequence of an unstable process and the new way of thinking that comes with SQC. Further, it aims to explore the relationship between cost optimisation and SQC. Adding a layer of complexity and understanding to the spread of Statistical Quality Tools and their importance for several industries. This will contribute to tightening the bonds of production economics, statistical tools and quality management even further.   Methods. This study made use of two closely related methodologies, combining SPC with Cost of Quality. The combination of these two hoped to demonstrate a possible cost reduction through stabilising the process. The cost reduction was displayed using an optimisation model based on the P-A-F (Prevention, Appraisal, External Failure and Internal Failure) and further developed by adding a fifth parameter for optimising materials (OM). Regarding whether the process was in control or not, we focused on the thickness of the PVC floor, 1008 data points over three weeks were retrieved from the production line, and by analysing these, a conclusion on whether the process was in control could be drawn.    Results. Firstly, none of the three examined weeks were found to be in statistical control, and therefore, nor were the total sample. Through the assumption of the firm achieving 100% statistical control over their production process, a possible cost reduction of 874 416 SEK yearly was found.    Conclusions. This study has proven that through focusing on stabilising the production process and achieving control over their costs related to quality, possible significant yearly savings can be achieved. Furthermore, an annual cost reduction was found by optimising the usage of materials by relocating the ensuring of thickness variation from post-production to during the production.

Yes / Wind Energy published by John Wiley & Sons Ltd. Maintenance is essential in keeping wind energy assets operating efficiently. With the development of advanced condition monitoring, diagnostics and prognostics, condition-based maintenance has attracted much attention in the offshore wind industry in recent years. This paper models various maintenance activities and their impacts on the degradation and performance of offshore wind turbine components. An integrated maintenance strategy of corrective maintenance, imperfect time-based preventive maintenance and condition-based maintenance is proposed and compared with other traditional maintenance strategies. A maintenance simulation programme is developed to simulate the degradation and maintenance of offshore wind turbines and estimate their performance. A case study on a 10-MW offshore wind turbine (OWT) is presented to analyse the performance of different maintenance strategies. The simulation results reveal that the proposed strategy not only reduces the total maintenance cost but also improves the energy generation by reducing the total downtime and expected energy not supplied. Furthermore, the proposed maintenance strategy is optimised to find the best degradation threshold and balance the trade-off between the use of condition-based maintenance and other maintenance activities. / UK Engineering and Physical Sciences Research Council (EPSRC). Grant Number: EP/P009743/1

This dissertation investigates the development of new Global system for mobile communications (GSM) improvement algorithms used to solve the nondeterministic polynomial-time hard (NP-hard) problem of assigning cells to switches. The departure of this project from previous projects is in the area of the GSM network being optimised. Most previous projects tried minimising the signalling load on the network. The main aim in this project is to reduce the operational expenditure as much as possible while still adhering to network element constraints. This is achieved by generating new network configurations with a reduced transmission cost. Since assigning cells to switches in cellular mobile networks is a NP-hard problem, exact methods cannot be used to solve it for real-size networks. In this context, heuristic approaches, evolutionary search algorithms and clustering techniques can, however, be used. This dissertation presents a comprehensive and comparative study of the above-mentioned categories of search techniques adopted specifically for GSM network improvement. The evolutionary search technique evaluated is a genetic algorithm (GA) while the unsupervised learning technique is a Gaussian mixture model (GMM). A number of custom-developed heuristic search techniques with differing goals were also experimented with. The implementation of these algorithms was tested in order to measure the quality of the solutions. Results obtained confirmed the ability of the search techniques to produce network configurations with a reduced operational expenditure while still adhering to network element constraints. The best results found were using the Gaussian mixture model where savings of up to 17% were achieved. The heuristic searches produced promising results in the form of the characteristics they portray, for example, load-balancing. Due to the massive problem space and a suboptimal chromosome representation, the genetic algorithm struggled to find high quality viable solutions. The objective of reducing network cost was achieved by performing cell-to-switch optimisation taking traffic distributions, transmission costs and network element constraints into account. These criteria cannot be divorced from each other since they are all interdependent, omitting any one of them will lead to inefficient and infeasible configurations. Results obtained further indicated that the search space consists out of two components namely, traffic and transmission cost. When optimising, it is very important to consider both components simultaneously, if not, infeasible or suboptimum solutions are generated. It was also found that pre-processing has a major impact on the cluster-forming ability of the GMM. Depending on how the pre-processing technique is set up, it is possible to bias the cluster-formation process in such a way that either transmission cost savings or a reduction in inter base station controller/switching centre traffic volume is given preference. Two of the difficult questions to answer when performing network capacity expansions are where to install the remote base station controllers (BSCs) and how to alter the existing BSC boundaries to accommodate the new BSCs being introduced. Using the techniques developed in this dissertation, these questions can now be answered with confidence. / Dissertation (MEng)--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted

[EN] Adaptation to the multiple facets of global change challenges the conventional means of sustainably planning and managing water resources at the river basin scale. Numerous demand or supply management options are available, from which adaptation measures need to be selected in a context of high uncertainty of future conditions. Given the interdependency of water users, agreements need to be found at the local level to implement the most effective adaptation measures. Therefore, this thesis develops an approach combining economics and water resources engineering to select a cost-effective programme of adaptation measures in the context of climate change uncertainty, and to define an equitable allocation of the cost of the adaptation plan between the stakeholders involved. A framework is developed to integrate inputs from the two main approaches commonly used to plan for adaptation. The first, referred to as "top-down", consists of a modelling chain going from global greenhouse gases emission scenarios to local hydrological models used to assess the impact of climate change on water resources. Conversely, the second approach, called "bottom-up", starts from assessing vulnerability at the local level to then identify adaptation measures used to face an uncertain future. Outcomes from these two approaches are integrated to select a cost-effective combination of adaptation measures through a least-cost optimization model developed at the river basin scale. The model is then used to investigate the trade-offs between different planning objectives defined in terms of environmental flow requirements, irrigated agriculture development, and the cost of the programme of measures. The performances of a programme of measures are finally assessed under different climate projections to identify robust and least-regret adaptation measures. The issue of allocating the cost of the adaptation plan is considered through two complementary perspectives. The outcome of a negotiation process between the stakeholders is modelled through the implementation of cooperative game theory to define cost allocation scenarios. These results are compared with cost allocation rules based on social justice principles to provide contrasted insights into a negotiation process. This innovative framework has been applied in a Mediterranean case study in the Orb River basin (France). Mid-term climate projections, downscaled from 9 General Climate Models, are used to assess the uncertainty associated with climate projections. Demand evolution scenarios have been developed to project agricultural and urban water demands on the 2030 time horizon. The least-cost river basin optimization model developed in GAMS allows the cost-effective selection of a programme of measures from a catalogue of 462 supply and demand management measures. Nine cost allocation scenarios based on different social justice principles have been discussed through face-to-face semi-structured interviews with 15 key informants and compared with solution concepts from cooperative game theory for a 3-player game defined at the river basin scale. The interdisciplinary framework developed in this thesis combines economics and water resources engineering methods, establishing a promising means of bridging the gap between bottom-up and top-down approaches and supporting the creation of cost-effective and equitable adaptation plans at the local level. / [ES] La adaptación a los múltiples aspectos del cambio global supone un reto para los enfoques convencionales de planificación y gestión sostenible de los recursos hídricos a escala de cuenca. Numerosas opciones de gestión de la demanda o de la oferta están disponibles, de entre las cuales es necesario seleccionar medidas de adaptación en un contexto de elevada incertidumbre sobre las condiciones futuras. Dadas las interdependencias existentes entre los usuarios del agua a nivel local, hace falta buscar acuerdos a escala de cuenca para implementar las medidas de adaptación más eficaces. Por este motivo, esta tesis desarrolla una metodología que, combinando economía e ingeniería de los recursos hídricos, busca seleccionar un programa de medidas coste-eficaz frente a las incertidumbres del cambio climático, y asimismo definir un reparto justo del coste de la adaptación entre los actores implicados. El marco metodológico ha sido desarrollado para integrar contribuciones de los dos principales enfoques utilizados para la planificación de la adaptación. El primero, denominado descendente ("top-down"), consiste en una cadena de modelación que va desde los escenarios de emisiones de gases efecto invernadero a nivel global hasta los modelos hidrológicos utilizados a nivel local para evaluar así el impacto del cambio climático sobre los recursos hídricos. Por el contrario, el segundo enfoque denominado ascendente ("bottom-up") empieza por evaluar la vulnerabilidad del sistema a nivel local para después identificar medidas de adaptación frente a un futuro incierto. Los resultados de los métodos mencionados previamente se han integrado con el fin de seleccionar una combinación coste-eficaz de medidas de adaptación a través de un modelo de optimización a menor coste a escala de cuenca. El modelo se utiliza para investigar las soluciones de compromiso ("trade-offs") entre diversos objetivos de planificación como son los caudales ecológicos necesarios, el desarrollo del regadío y el coste del programa de medidas. Seguidamente, se han evaluado los programas de adaptación frente a varias condiciones climáticas para definir así un programa de medidas robusto y de arrepentimiento mínimo frente al cambio climático. En la última parte se aborda el problema del reparto justo de los costes del plan de adaptación, entendiendo que esto es una manera de favorecer su implementación. Para ello, se han modelado los resultados de un proceso de negociación entre los diferentes actores mediante escenarios de reparto basados en la teoría de juegos cooperativos. Posteriormente, se han comparado estos resultados con otras reglas de reparto de costes basadas en principios de justicia social, proporcionando así un punto de vista diferente al proceso de negociación. Este novedoso enfoque ha sido aplicado a una cuenca mediterránea, la cuenca del rio Orb (Francia). Para ello, se han empleado proyecciones climáticas a medio-plazo de datos reescalados de 9 Modelos de Circulación Global. Además, se han desarrollado escenarios de evolución de la demanda en los sectores urbano y agrícola para el horizonte de planificación de 2030. El modelo de optimización a menor coste a escala de cuenca desarrollado en GAMS permite seleccionar un programa de medidas, de entre las 462 medidas de gestión de la oferta o de la demanda. Nueve escenarios de reparto de costes basados en diferentes principios de justicia social han sido debatidos con informantes clave mediante entrevistas y comparados con conceptos de solución de la teoría de juegos cooperativos, considerando un juego de 3 jugadores a escala de cuenca. El marco interdisciplinario desarrollado durante esta tesis combina métodos de economía y de ingeniería de los recursos hídricos de manera prometedora y permite integrar los enfoques "top-down" y "bottom-up", contribuyendo a definir un plan de adaptación coste-eficaz y justo a nivel local. / [CA] L'adaptació als múltiples aspectes del canvi global implica un repte per als enfocaments convencionals de planificació i gestió sostenible dels recursos hídrics a escala de conca. Existeixen nombroses opcions de gestió de la demanda y de la oferta. De entre elles, cal seleccionar mesures d'adaptació en un context d'incertesa elevada sobre les condicions futures. Donades les interaccions entre els usuaris de l'aigua a nivell local, és necessari buscar acords a escala de conca per tal d'implementar les mesures d'adaptació més eficaces. Per aquest motiu, la tesi desenvolupa una metodologia que, mitjançant la combinació d'economia i enginyeria dels recursos hídrics, siga adient per seleccionar un programa de mesures cost-eficaç per a fer front a les incerteses del canvi climàtic i, a més a més, definir un repartiment just del cost d'adaptació entre els actors implicats. El marc metodològic ha estat desenvolupat amb el fi de permetre integrar contribucions del principals enfocaments que s'utilitzen per a la planificació de l'adaptació. El primer, que es denomina descendent ("top-down"), consisteix a una cadena de modelació que va des dels escenaris d'emissions de gas d'efecte hivernacle a nivell global fins als models hidrològics a nivell local per avaluar l'impacte del canvi climàtic sobre els recursos hídrics. Per contra, el segon enfocament, que es denomina ascendent ("bottom-up"), comença per avaluar la vulnerabilitat del sistema a nivell local per a tot seguit identificar mesures d'adaptació de cara a un futur incert. Els resultats del mètodes esmentats prèviament, s'han integrat per a seleccionar una combinació de mesures d'adaptació cost-eficaç mitjançant un model d'optimització a menor cost a escala de conca. El model s'utilitza per investigar les solucions de compromís ("trade-offs") entre els diversos objectius de planificació, com són els cabals ecològics necessaris, el desenvolupament del regadiu i el cost del programa de mesures. A continuació, s'avaluen els programes d'adaptació per a varies condicions climàtiques amb el fi de definir un programa de mesures robust i de penediment mínim per a fer front al canvi climàtic. En la darrera part, s'escomet el problema del repartiment just dels costs del pla d'adaptació, considerant que això és una manera de facilitar la implementació del pla. En conseqüència, els resultats d'un procés de negociació entre els diferents actors han estat modelats mitjançant escenaris de repartiment basats en la teoria de jocs cooperatius. Tot seguit, els resultats s'han comparat amb altres regles de repartiment de costos basades en principis de justícia social. Això ha proporcionat un punt de vista diferent al procés de negociació. Aquest enfocament innovador s'ha aplicat a una conca mediterrània, la conca del riu Orb (França). Amb aquesta finalitat s'han utilitzat projeccions climàtiques a mig termini de dades reescalades de 9 Models de Circulació Global (MCG). A més a més, s'han desenvolupat escenaris d'evolució de la demanada en els sectors agrícola i urbà per a l'horitzó de planificació de 2030. El model d'optimització a menor cost a escala de conca desenvolupat en GAMS permet seleccionar un programa de mesures, de entre les 462 mesures de gestió de la oferta o de la demanda. Els nou escenaris de repartiment de costs han estat debatuts amb informants clau, mitjançant entrevistes, i comparats amb conceptes de solució de la teoria de jocs cooperatius, considerant un joc de 3 jugadors a escala de conca. El marc interdisciplinari desenvolupat al llarg de la tesi combina mètodes d'economia i d'enginyeria dels recursos hídrics de manera prometedora i permet la integració d'enfocaments "top-down" i "bottom-up", fet que contribueix a definir un pla d'adaptació cost-eficaç i just a escala local. / Girard, CDP. (2015). Integrating top-down and bottom-up approaches to design a cost-effective and equitable programme of measures for adaptation of a river basin to global change [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59461 / Premios Extraordinarios de tesis doctorales