Abstract
A área de conhecimento associada à gestão de ativos potencia a extração de valor de ativos físicos, incorporando uma abordagem integrada que envolve riscos, custos e desempenho. Este trabalho propõe uma nova abordagem para selecionar projetos de investimento em infraestruturas no âmbito da gestão de ativos. A métrica padrão utilizada para a seleção de projetos em ativos múltiplos é o Índice de Valor de Infraestruturas (IVI), que tem sido utilizado para caracterizar ativos do setor de águas em diversos países. Este trabalho desenvolveu dois modelos de programação linear inteira mista. O primeiro modelo de otimização trata de um problema de alocação de orçamento de capital selecionando projetos de investimento com vista à maximização da condição dos ativos. O segundo modelo de otimização trata de um problema de planeamento de orçamento, visando minimizar o capital necessário para manter os ativos nas condições desejadas. A aplicação dos modelos é ilustrada por um estudo de caso de uma empresa que opera no setor da água em Portugal. Os resultados obtidos nos diferentes cenários analisados são discutidos com vista a apoiar o desenho de políticas de gestão de ativos mais eficientes.

Abstract
Purpose - The World State of Quality (WSQ) Project aims to evaluate, analyse, rank and categorise countries according to their performance in quality as a multidimensional concept. The Project involves the computation of an overall score for each country, obtained as a weighted average of ranking positions of 16 metrics, with weights determined by a panel of experts. Methodology-This work proposes an alternative strategy for that procedure, using a Benefit-of-the-Doubt (BoD) Composite Indicator approach under the framework of Data Envelopment Analysis (DEA). This strategy avoids the need of using subjective weights and normalising data by rank positions, using a more objective procedure to obtain the countries’ ranking. A new overall score of the World State of Quality is proposed, which allows the categorisation of countries’ performance. The novel insights resulting from the use of this methodology are discussed, including the identification of strengths and weaknesses of the various countries, and the peers that can be used for facilitating continuous improvements policies. Findings - The results show that the BoD approach and the original method used by the WSQ Project present comparable results. Countries’ strengths and weaknesses and their suitable peers and targets for benchmarking are presented with illustrative examples. Originality/value – A novel frontier approach for countries’ benchmarking regarding their performance in quality is proposed, incorporating new insights into the current method. © 2022 Universidade do Minho. All rights reserved.

Abstract
A benchmarking evaluation instrument was designed with a European Union country regulatory authority for water supply and wastewater treatment services to determine the efficient operating cost of its service providers that operated in the wholesale market segment in the 2017-2021 period. To this end, the non-parametric Data Envelopment Analysis technique was adapted to a robust and conditional approach. The results point to similar mean efficiency scores between water supply and wastewater services in the five-year period, despite the greater heterogeneity in the latter. Furthermore, the estimated potential cost savings for both services ranged from about 2% to 3%.

Abstract
This research evaluates the performance of water supply utilities operating at the retail level in Portugal concerning asset management practices. The study's main innovative feature is identifying peers and targets to guide improvements in the sector. Reliable data collected by the regulatory authority for water and waste services in Portugal (ERSAR) are employed to design two composite indicators reflecting different dimensions of asset management: operational conditions and management systems. Based on the Data Envelopment Analysis technique, the Benefit-of-the-Doubt model is employed in robust and conditional formulations. The role of the context on utilities' performance is also investigated. The results show that the direct management model is unfavourable concerning developing structured management systems, whilst urban environments favour managerial advancement. Rural and semi-urban environments favour goodoperational results in infrastructures. The pool of peers obtained for each utility and the quantification of targets based on the observed achievements by those peers facilitates the search for industry best practices and promotes continuous improvement. Given the high heterogeneity in asset management performance within the sector, the utility-specific target-setting approach illustrated in this paper can support a regulatory policy review for determining more realistic goals.

Abstract
This study explores asset management performance of Portuguese water supply companies operating in the bulk market. The focus of the analysis are the managerial practices and the condition of infrastructures. This assessment is based on the information conveyed by the indicators collected by the Portuguese water and waste services' regulator authority (ERSAR) between 2016 and 2020. The main contribution of this research is to propose innovative methods to enhance the knowledge on asset management practices in the water sector. Two Benefit-of-the-Doubt (BoD) Composite Indicators are developed to highlight different aspects of asset management approaches. The first reflects organisations' performance in maintaining their infrastructures at acceptable operational levels, and the other reveals their maturity in asset management practices. Robust and conditional approaches for estimating the BoD indicators are applied, allowing to obtain results that account for the effect of contextual variables on companies' performance. Additionally, the performance of the companies is analysed over a 5-year period. The results show that there is significant room for improvement given the indicators' values estimated in the benchmarking analysis. The type of management systems and areas of intervention (urban, semi-urban or rural) are factors that present significant impact in asset management performance. The analysis of trends in the evolution of performance over time revealed improvements both in the companies' managerial practices and operational results.

Abstract
A significant challenge in asset management is the selection of investment projects for infrastructures, which often relies on subjective judgement and lacks structured decision support methods. This challenge is particularly complex in water systems due to the diverse and heterogeneous nature of the components requiring investment. While the infrastructure value index (IVI) is widely used to characterise assets and support investment decisions in the water sector, its application in optimisation models for generating efficient project portfolios remains unexplored. To address this research gap, this study introduces optimisation models for generating investment portfolio plans in water systems' asset management. The proposed approach includes two mixed-integer linear programming (MILP) models that determine optimal solutions and an evolutionary algorithm that offers sub-optimal alternative investment selection plans to provide decision-makers with additional choices for balancing optimal outcomes. The primary contribution of this research is the combined utilisation of MILP and evolutionary algorithms, integrating the IVI into the decision-making process. These tools provide decision-makers with structured methods for defining investment plans and minimising the subjective elements typically associated with such processes. To illustrate the effectiveness of the models, a case study is presented involving a pumping station of a Portuguese water company. The results demonstrate the practical application and benefits of the proposed approach in optimising investment decisions. This research contributes to advancing asset management practices by integrating quantitative optimisation techniques and leveraging the IVI, thereby enhancing the objectivity and efficiency of investment planning in water systems' asset management.