Although many scholars assert that portfolio approach can facilitate purchasing to live up to its strategic importance and contribute to company performance; and practitioners have applied portfolio approach in various purchasing activities, there are still limited empirical researches to confirm that portfolio can actually create the benefits. The purpose of the study is to explore the usefulness of portfolio approach as well as why companies decide to apply portfolio approach in purchasing and supply management. Based on an international survey carried on a large number of European and North American manufacturing companies, the findings of the study provide strong evidence on the significant impact that the purchasing portfolio approach has on the business results, and also shed lights on the strategic importance of purchasing as a direct explanation to the application of the approach by companies. The empirical study confirms that the competency of the purchasing professionals plays a prominent role on the path of transforming the strategic importance of purchasing, with the help of portfolio approach, to the success of improved purchasing performance. A cross-discipline theoretical study reveals that different models share a common theoretical foundation and consist of similar basic elements in their construct. The results of this study fill the research gap in analyzing the causes of the application of portfolio approach; provide quantitative empirical proof on the usefulness of portfolio approach in the industrial companies and thus give support to the existing theories. The study contributes to a growing research stream on how to improve purchasing business performance, reflecting the increasing strategic role that purchasing is given. The results send useful messages to company managements and provide valuable insights on an important tool for improving purchasing business performance.

South African legislation, as summarised in The Strategic Framework for Water Services (Department of Water Affairs and Forestry, 2003), makes local authorities responsible for all water services to individual consumers. As Water Services Authorities (WSAs), municipalities must appoint Water Services Providers (WSPs) to implement water services. The legislation allows a range of organisations to act as WSPs. The Strategic Framework also lays down norms and standards with regards to continuity of water supplies and water quality. The country has adopted a policy of "Free Basic Water", which requires WSAs to provide a basic level of services free of charge. Six kilolitres per household per month is the norm adopted by most municipalities. In deciding on the institutional arrangements for the provISIon of water serVIces, municipalities need to decide what functions, if any, to outsource. Most international literature that reviews experiences of the International Water Decade advocates community management of rural water supplies, pointing to failures of government run, centralised management of rural schemes. A strong reason given for choosing community management is the sense of "ownership" this gives to local communities. Traditional theories on management by government organisations use a "steering" model, in which the government sets the course for policy and administrators implement the policies decided upon. Since the 1980s, a new paradigm for analysing government has emerged, emphasising the limits to governments' power to act as it wishes. The new model is one of networks of various interdependent organisations, often with the government at the centre. Such a model can be used to depict organisational relationships in rural areas of South Africa. In the early 1990s, a number ofNGOs implemented rural water schemes using the community management approach. However, after the passing of legislation making municipalities WSAs, very few municipalities have seriously considered community management, or any formal role for local community based organisations. Efforts to assess the effectiveness of municipalities' water service delivery IS severely hampered by a lack of usable data. Since starting to take responsibility for water schemes from DWAF and other bodies in 2000, municipalities have struggled to manage service delivery effectively, largely due to a shortage of management and technical skills. Alfred Nzo District Municipality (ANDM) is one of the poorest municipalities in the country, with high levels of poverty. Approximately 50% of the rural population have adequate water services, that is 25 litres per person available within 200 metres of the household (Smith, 2006). The operation of services is paid mainly from the municipality's equitable share from national government. This report attempts to assess the effectiveness and efficiency of community management of rural water supplies. This is done by examining ANDM's community management model as a case study. The roles and responsibilities of various actors in the programme were analysed by interviewing the Support Services Agents (SSAs) engaged to co-ordinate the programme. The effectiveness of the water services were analysed using the SSAs' monthly reports, and this was compared with other available data. The experiences of other rural municipalities were also examined, focusing on their experiences with community participation. The model used by ANDM consisted of a water committee or board for each water scheme, which supervised the work of local operators and administrators. Operators carried out minor repairs, while the SSAs did monthly servicing of pumps and motors, and implemented major repairs, largely by supervising local operators and casual labourers. Committees submitted monthly reports to the SSAs, which were used as a basis for reports from the SSAs to the municipality. SSAs also reported on water quality. The figures for continuity of supply (measuring the operability of the infrastructure) varied considerably between the three SSAs. A possible reason for low figures from one SSA was that the figures also reflected water shortages in some schemes. Figures for water quality varied more than those for continuity, leading to a concern about the extent to which sampling and testing procedures were standardised. The figures were compared with figures from attitude surveys on water services recording consumers' perceptions about continuity of supply. The difference in data being measured, and concerns about the meaning of the figures from the SSAs' reports make direct comparisons impossible. However, the data indicates that for schemes served by two of the SSAs at least, a reasonably effective service was rendered. The cost to the municipality of providing water services was R4,19 per person per month, a relatively low figure compared with other municipalities. The four KwaZulu-Natal District Municipalities interviewed all reported negative experiences with community management of rural schemes that they inherited, and all four have opted for a centralised system, one using a partnership with a water board. None of the four municipalities had systematic data on continuity of service. Despite the difficulties in comparing the performance of ANDM to that of other municipalities, it is clear that the system employed by the municipality to use community management with the support of external consultants and NGOs was workable, sustainable and efficient. The participation of local community organisations assisted in some of the common problems that beset rural water schemes such as vandalism and water wastage. The report recommends that: • Municipalities with remote rural water schemes seriously consider community management as an effective and efficient delivery mechanism. • Where community management is employed, it is backed up with effective managerial and technical support. • The Alfred Nzo District Municipality reinstate the contracts with external Support Services Agents, which were the basis of effective management of and reporting on its rural water supply programme, unless equivalent internal capacity has been acquired to do the work done by the Support Services Agents. • Water Services Providers be required by water services authorities to submit regular data on service availability, continuity of supply and water quality, and Water Services Authorities in turn be required to submit similar data to DWAF. • DWAF issues guidelines on how proper separation of regulation and implementation roles be effected between WSAs and WSPs respectively when the WSP function is carried out internally. / Thesis (M.B.A.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

Much has been written about the desperate need to seek alternative solutions to the urban traffic congestion problems we face today. To manage these problems, three main streams of intervention have evolved from supply, demand and land-use management paradigms. Whilst their underlying measures all have the ability to reduce traffic congestion one way or another, little has been done to integrate the measures of each stream using a qualitative decision framework or process enabling the selection of site specific measures appropriate to local traffic and transport conditions. To this end the study reports the results of an empirical investigation by which a Multi-Criteria Analysis based Dynamic Adaptive Decision Framework (D.A.D.F.) were developed. This screens selected measures identifying those that have the potential to alleviate site specific road based traffic congestion. The product of the screening process is a set of sustainable measures transposed into an integrated strategy tailored to address local traffic congestion issues. Once the D.A.D.F. was developed, its usefulness and workability was tested by applying it to a case study. The case study results demonstrated that the D.A.D.F. is capable of producing integrated strategies with the ability to manage traffic congestion, encourage sustainable development and alleviate some site specific development challenges within the context of the study areas. Going beyond developing the decision framework, the study recommends positioning the D.A.D.F. within the South African planning system as part of a Traffic Congestion Management Plan (T.C.M.P.), setting out its likely components within the local context. It is concluded that the main innovation of the study is the development of the D.A.D.F., the T.C.M.P., the recommendations to situate both in the planning system and the comprehensive, but still transparent, approach undertaken to create integrated strategies for specific local conditions consisting of elements that work together to produce cumulative short to long term effects that attain a balanced set of environmental, social and economic goals - all imperative for sustainable development. / Thesis (Ph.D. (Town and Regional Planning))--North-West University, Potchefstroom Campus, 2008.

Much has been written about the desperate need to seek alternative solutions to the urban traffic congestion problems we face today. To manage these problems, three main streams of intervention have evolved from supply, demand and land-use management paradigms. Whilst their underlying measures all have the ability to reduce traffic congestion one way or another, little has been done to integrate the measures of each stream using a qualitative decision framework or process enabling the selection of site specific measures appropriate to local traffic and transport conditions. To this end the study reports the results of an empirical investigation by which a Multi-Criteria Analysis based Dynamic Adaptive Decision Framework (D.A.D.F.) were developed. This screens selected measures identifying those that have the potential to alleviate site specific road based traffic congestion. The product of the screening process is a set of sustainable measures transposed into an integrated strategy tailored to address local traffic congestion issues. Once the D.A.D.F. was developed, its usefulness and workability was tested by applying it to a case study. The case study results demonstrated that the D.A.D.F. is capable of producing integrated strategies with the ability to manage traffic congestion, encourage sustainable development and alleviate some site specific development challenges within the context of the study areas. Going beyond developing the decision framework, the study recommends positioning the D.A.D.F. within the South African planning system as part of a Traffic Congestion Management Plan (T.C.M.P.), setting out its likely components within the local context. It is concluded that the main innovation of the study is the development of the D.A.D.F., the T.C.M.P., the recommendations to situate both in the planning system and the comprehensive, but still transparent, approach undertaken to create integrated strategies for specific local conditions consisting of elements that work together to produce cumulative short to long term effects that attain a balanced set of environmental, social and economic goals - all imperative for sustainable development. / Thesis (Ph.D. (Town and Regional Planning))--North-West University, Potchefstroom Campus, 2008.

Water resources management practice has undergone changes in management approaches and principles over time. It was previously characterised by what scholars refer to as the hydraulic mission where ‘extreme engineering’ was the order of the day (Allan, 2003). As Radif (1999) argues, water resources managers and policy makers were initially driven to manage and supply water to people for its direct use / these included drinking, growing food, and providing power for domestic and industrial use. This modus operandi continued until the end of the 1970s. Over two decades later, this focus is still prevalent in many countries in southern Africa including Botswana. As Swatuk and Rahm (2004) state, “augmenting supply is a continuing focus of government activity”. The National Water Master Plan (NWMP) is the current policy document guiding water resources management in Botswana and it focuses on supply-side interventions in response to increasing water demand. According to SMEC et al. (1991), the consulting company that conducted the NWMP study, “the investigation and studies... indicated the need for the continuing development of water supplies throughout Botswana over the next 30 years”. Based on these observations, government has developed significant human and technical capacity in exploiting both surface and groundwater resources (Swatuk and Rahm, 2004).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The demand for water in the various sectors of society is increasing due to factors such as population growth, expansion of agricultural land, depletion of water resources and water quality decreased. Among these uses these demands arise that there are two groups of water, consumptive and non-consumptive. Consumptive uses are characterized by causing a change in the quantity or quality of water, either through funding or evictions. Non-consumptive uses do not cause significant changes in the quantity and quality of water, but depend on these to be realized. The irrigation of rice is a consumptive use that is considered high pollution impact by demanding too much water in their production process. The Rio Grande do Sul is responsible for approximately 65% of rice production in Brazil. The watershed of the river Santa Maria, is characterized by having focused their economic bases for rice cultivation and livestock. In the past there have been conflicts over water use between sectors of users of the basin (water supply and irrigation). Thus, this paper proposes the creation of scenarios with the gradual reduction in a range of 1% to 15% in the demand of water for irrigation of rice in funding of water held in the rivers in BHRSM. With the aim of analyzing the results proposed to the management of water demand can assist and serve as input for the process of water resources management. Initially 5 scenarios, Scenario 0, which characterizes the present moment basin, Scenario 1, 2, 3 and 4 which have as a methodological proposal to reduce the demand for water for irrigation were built. The results obtained in this work allow us to analyze the management of water demand can help to increase water availability. The scenarios simulated for the months from November to February showed the highest percentage of attendance when compared to current demand. However, the month of January still has some hydrological drought in reference sections, being necessary to think about rationing or the use of available water in existing reservoirs in the basin. It is estimated that the results obtained with the simulation in demand management, can support the management of water resources of the basin. / A demanda por água nos diversos setores da sociedade vem aumentando devido a fatores como: crescimento populacional, expansão das áreas agrícolas, esgotamento dos recursos hídricos e diminuição da qualidade água. Entre estes usos que originam estas demandas de águas existem dois grupos, os consuntivos e não consuntivos. Os usos consuntivos caracterizam-se por causarem alguma alteração na quantidade ou qualidade da água, seja por meio de captações ou despejos. Os usos não consuntivos não causam alterações significativas na quantidade e qualidade da água, porém dependem destas para serem realizados. A irrigação de arroz é um uso consuntivo que é considerado de alto impacto poluidor por demandar muita água no seu processo produtivo. O Rio Grande do Sul é responsável por aproximadamente 65% da produção de arroz no Brasil. A Bacia Hidrográfica do rio Santa Maria, caracteriza-se por ter suas bases econômicas voltadas para orizicultura e pecuária de corte. No passado existiram conflitos pelo uso da água entre os setores de usuários da bacia (abastecimento e irrigação). Desta forma, este trabalho propõe a criação de cenários com a redução gradual, em uma escala de 1% a 15% na demanda de água destinada a irrigação do arroz, nas captações de águas realizadas nos rios na BHRSM. Com o objetivo de analisar se os resultados propostos com a gestão da demanda de água podem auxiliar e servir como subsídios para os processos de gestão de recursos hídricos. Foram construídos inicialmente 5 cenários, o Cenário 0, que caracteriza o momento atual da bacia, Cenário 1, 2, 3 e 4 que possuem como proposta metodológica a redução na demanda de água destinada a irrigação. Os resultados obtidos com neste trabalho permitem analisar que a gestão da demanda de água pode auxiliar no aumento da disponibilidade hídrica. Os cenários simulados para os meses de novembro a fevereiro apresentaram percentuais de atendimento da demanda maiores quando comparado ao atual. No entanto, o mês de janeiro ainda apresenta déficit hídrico em algumas seções hidrológicas de referência, sendo necessário pensar em racionamento ou a utilização das águas disponíveis em reservatórios já existentes na bacia. Estima-se que os resultados obtidos com a simulação na gestão da demanda, possam subsidiar o gerenciamento dos recursos hídricos da bacia.

Submitted by Ronildo Prado (ronisp@ufscar.br) on 2016-09-27T14:17:21Z No. of bitstreams: 1 DissRCS.pdf: 1598751 bytes, checksum: 42cb8bbd25b7caf1f07d24be0b96b823 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-09-27T14:17:39Z (GMT) No. of bitstreams: 1 DissRCS.pdf: 1598751 bytes, checksum: 42cb8bbd25b7caf1f07d24be0b96b823 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-09-27T14:17:48Z (GMT) No. of bitstreams: 1 DissRCS.pdf: 1598751 bytes, checksum: 42cb8bbd25b7caf1f07d24be0b96b823 (MD5) / Made available in DSpace on 2016-09-27T14:17:55Z (GMT). No. of bitstreams: 1 DissRCS.pdf: 1598751 bytes, checksum: 42cb8bbd25b7caf1f07d24be0b96b823 (MD5) Previous issue date: 2016-03-09 / Não recebi financiamento / The Federal University of São Carlos is part of the current period of expansion of courses and vacancies in the Federal Institutions of Higher Education (IFES), especially after REUNI (Support Program Plan of Restructuring and Expansion of Federal Universities). In order to meet the demand of a growing institution, took effect several administrative changes. One of the changes underway is the implementation of decentralized units of shopping, which is the object of study. This research has the following objectives: identify the factors inherent to this process (steps, difficulties, solutions, benefits, etc.), as well as the impacts of the changes made in the organizational structure generated in the administration of the University, map the new organizational structure Dean of administration (PROAD), identify problems and propose solutions and changes in procedures that may assist in the execution of decentralized purchasing activity. To this end, research is proposed as an action research with qualitative approach with exploratory way, designed as a single case study, the Federal University of São Carlos (UFSCar). / A Universidade Federal de São Carlos está inserida no atual momento de expansão de cursos e vagas nas Instituições Federais de Ensino Superior (IFES), principalmente após o REUNI (Programa de Apoio ao Plano de Reestruturação e Expansão das Universidades Federais). De forma a atender a demanda de uma instituição em crescimento, passaram a vigorar várias mudanças administrativas. Uma das mudanças em andamento é a implementação de unidades descentralizadas de compras, que é o objeto de estudo. A presente pesquisa apresenta como objetivos: identificar os fatores inerentes a esse processo (etapas, dificuldades, soluções, benefícios, entre outros), assim como os impactos que as mudanças realizadas na estrutura organizacional geraram na administração da Universidade, mapear a nova estrutura organizacional da Pró-reitoria de administração (ProAd), identificar dificuldades e propor soluções e mudanças em procedimentos internos que possam auxiliar na efetivação da descentralização da função de compras. Para tanto, a pesquisa se propõe como uma pesquisaação, com abordagem qualitativa, com propósito exploratório, delineada como estudo de caso único, a Universidade Federal de São Carlos (UFSCar).

Este trabalho objetivou determinar a disponibilidade do aqüífero Serra Grande e estabelecer as diretrizes para o seu gerenciamento sustentável no município de Picos, localizado no sudeste do Estado do Piauí. Principal sistema de água subterrânea da região, este aqüífero é o único com capacidade para atender as demandas futuras da população. Porém, a falta de regras básicas na exploração dos seus recursos poderá comprometer sua sustentabilidade. O desenvolvimento deste estudo teve início com a elaboração do modelo conceitual da área e a análise das condições de uso dos recursos hídricos. Nesta etapa, verificando-se que os conceitos hidrogeológicos vigentes consideravam apenas o limite físico do sistema para definir sua disponibilidade, foi estabelecido um novo princípio para determinação do volume de recursos que pode ser explorado de um aqüífero, denominado de princípio sustentável, tendo como base os fatores econômicos envolvidos na sua exploração. Para determinação da disponibilidade física e econômica do aqüífero Serra Grande, primeiramente, foi estimado o déficit hídrico acumulado desde o início da exploração do sistema, estabelecida sua relação com a posição do nível potenciométrico e calculado o custo atual de produção da água. Em seguida, foram traçados dois cenários futuros para a exploração dos recursos hídricos no município, representando os modelos de gestão da oferta e gestão da demanda, para o período de 15 e 50 anos. Posteriormente, foi construído um modelo matemático para representar o sistema de subsuperfície, no qual foi simulada a evolução futura do nível d’água. Com base nos valores obtidos, foi estimado o volume de água a ser produzido do armazenamento, a quantidade de recursos que deverão ser incorporados ao sistema e o custo futuro de produção. Os resultados mostraram que o aqüífero precisará incorporar um volume significativo de recursos, que talvez não esteja disponível na região estudada, e que a elevação real do custo da água poderá comprometer a capacidade de pagamento da população para dispor destes recursos. Verificada esta situação, foram definidas as medidas que precisam ser implementadas para o gerenciamento sustentável do aqüífero estudado, de modo a garantir o abastecimento futuro do município e da região. Com a elaboração deste trabalho, concluiu-se que o aqüífero Serra Grande não é “intensamente explorado” em Picos, porém é mal explorado atualmente, o que deverá provocar prejuízos na exploração futura dos seus recursos. / This work’s goals were to determinate the availability of the Serra Grande aquifer and to establish the governess for its sustainable management in the municipality of Picos, located on the southeast of Piauí State. This aquifer, the region’s most important groundwater system, has an unique capacity of fulfilling the population’s future demand. However, the absence of basic rules for the exploitation of its resources would compromise its sustainability. The study began with the development of the conceptual model of the area and the analyses of the water resources use. During this step, after verify that the hydrological actual concepts only observe the physical limit of the system to define its availability, it was established a new principle to determinate the volume of resources that can be exploited from an aquifer, named sustainable principle, based on the economical factors involved in its exploitation. In order to determine the physical and economical availability of the Serra Grande aquifer, first, it was estimated the water deficit accumulated since the begging exploitation of the system, established its relationship with the potenciometric level and was calculated the present cost of water production. Later on, two hypothetical scenarios concerning future exploration of water resources were drawn, representing the models of supply and demand management, for a period of 15 and 50 years. Furthermore, a mathematic model was built to represent the subsurface system, which was simulated the evolution of the water level. Based on the values found, it was estimated the amount of water that should be produced from storage, the quantity of resources that have to be incorporated to the system and the future production cost. Moreover, the results showed that the aquifer will need to incorporate a meaningful quantity of resources, that may be not available in the studied region, and that the real increase of the cost of the water would compromise the payment capacity of the population to dispose those resources. After verify this situation, it was defined the actions that must be taken for the sustainable management of the studied aquifer, to guarantee the future water supply of the municipality and the region. In conclusion, this work confirmed that the Serra Grande aquifer is not “overexploited” in Picos, instead, it is not being correctly exploited, which will negatively affect the future exploitation of its resources.

En la presente tesis se investigó sobre si las mejoras en la gestión de abastecimiento de filtros y alistamientos, optimizaría el tiempo de entrega al área de servicio técnico de la empresa CGM RENTAL S.A.C., ya que estas demoras han suscitado que el área de servicio técnico no pueda realizar los mantenimientos oportunos de los equipos ocasionando que los equipos presenten problemas por mal funcionamiento, desmovilización de equipos en obra , retrasos en los despachos de los equipos, entre otras lo que representa una pérdida considerable de ingresos para la empresa. Se expone como objetivo mejorar la gestión de abastecimiento; para lo cual se plantea identificar el nivel de rotación de los filtros y alistamientos; calcular sus stocks de seguridad e implementar una correcta planificación de compras. Se utilizó la información obtenida del sistema SAP (Sistemas, Aplicaciones y Producto) para poder comparar el estado de las atenciones al inicio de la tesis con el estado de las atenciones una vez aplicadas las mejoras; para ello se tomó una muestra de 341 OTS (ordenes de trabajo del área de servicio técnico) se utilizaron tablas dinámicas, diagrama de Pareto entre otros conocimientos propios de la ingeniería así como un análisis detallado de la información Se logró confirmar nuestra hipótesis ya que identificando los repuestos de alta rotación, calculando sus stocks de seguridad y mejorando la gestión de compras, se llegó a reducir el tiempo de entrega a servicio técnico. In this thesis we investigated whether improvements in the management of supply of filters and setups, optimize the time of delivery to the area of technical service of the company CGM RENTAL SAC, as these delays have raised the area of service no can make timely maintenance of equipment causing equipment malfunction problems arise, demobilization of equipment on site, delays in deliveries of equipment, including representing a considerable loss of revenue for the company. It is exposed aimed at improving the management of supply; which it is proposed to identify the level of rotation filters and setups; calculating their stocks up and implement proper procurement planning. Information obtained from SAP (Systems, Applications and Products) was used to compare the state of the attention at the beginning of the thesis with the state of the attention once implemented improvements; For this, a sample of 341 OTS (work orders service area) took pivot tables were used, among others Pareto own knowledge of engineering and a detailed analysis of the information They managed to confirm our hypothesis as identifying parts of high rotation, calculating their safety stocks and improving procurement management, it was to reduce the time for service delivery.

The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.