When evaluating and applying asset management concepts, water companies can face challenges in enabling targeted recommendation-making due to difficulties in accessing and processing of large volumes of data. These factors can lead to entrance barriers in utilization of breakdown data when assessing network reliability and scope of attainable improvements in asset strategy and maintenance concepts. Proven solutions and contextualized research are not readily available for water companies which, as asset-intensive enterprise relying on physical assets to deliver water to its customers, have a big stake in optimizing its use of data. This project has set out to research whether aspects of recommendation making for asset management at water companies can be aided with application of commonly available and deployable business intelligence tools. To this end, a water company which faces similar challenges has been selected. Evides – a water provider in the region of Rijnmond seeks more data-driven approaches in asset management of water connections. This asset group can be characterized by high volume, high technological heterogeneity and high absolute number of breakdowns as compared to distribution pipes. Together with a vast volume of data, this combination of factors leads to challenges in maintaining a continuous oversight and transparent conversion of performance data into strategic goals and clear service level agreements. The case of Evides inspired a research approach in which application of a custom-made decision support system is evaluated for the process of recommendation making in asset management of water connections. Methodology for this research encompassed for semi-structured interviews with network specialists and managers to obtain information on current asset management goals and the corresponding recommendation-making process for water connections. Thereafter, a thematic analysis was conducted to distill the main themes depicting aspects of interests to network-specialists in charge of producing recommendations and to managers – the decision makers. The type and moments at which performance data is processed and consulted were described and positioned in a managerial decision-making model, together with aspects assessed at each stage. Simple performance indicators were selected to aid the assessments and to connect performance readings with company goals. Findings were thereafter embedded into a purpose-made prototype of a decision support system, utilizing capacity of business intelligence software in creating curated datasets and user-friendly front end. In the last phase of the research, network specialists participated in appraisal of the created tool by completing a series of tasks designed to assess performance of water connections. Surveys were then conducted among participants to evaluate the added value of the created tool in the context of recommendation-making for asset management of water connections at Evides. Results show that, for the case study company, the created tool allows for improvements in accessibility and connectivity of company performance data and can contribute towards greater transparency in goal setting and enabling data-driven recommendation making for asset management of water connections. Performance outliers and policy non-compliers can be localized easier and help company in localizing areas in need of attention. Display of simple performance indicators for connections as per user-selected criteria can in the long run enable more nuances in describing network performance, shifting away from binary descriptions of asset’s performance. In case of Evides, the performance management framework for water connections was discovered as insufficiently defined to allow for assessments of direct benefits as result of application of the designed decision support-system. It is therefore recommended for future research to apply similar methodology for asset groups with well defined performance management standards and to focus on experimental design with higher external validity. ... Read more

Over the past decade, the complexity of operations in the port area has increased significantly. As global trade increased significantly, vessel sizes and cargo volumes surged, which places additional pressure on the ports' (physical) assets. Both the challenges the ports are facing and the willingness to ensure continuous improvement have contributed to a growing interest in benchmarking. Four European ports - Port of Rotterdam, North Sea Port, Port of Hamburg, and Port of Gothenburg - entered into a cooperation to realise a platform for benchmarking. Currently, limited research is available on methods for assessing and comparing asset management performance. This research aims at filling the gaps in literature by developing an international benchmarking model for ports. In doing so, it provides asset managers a structured approach to develop benchmarks in order to measure and compare performance. By combining existing frameworks and the consultation of experts in the research field, a model design is obtained in a collaborative way. The model is demonstrated by means of a case study. Following this demonstration it can be stated that the benchmarking model provides asset managers a clear working method and supporting tools. The presented benchmark results, and the process itself, provides asset managers valuable insights into performance. Consequently, it provides support in the development of future benchmarks. ... Read more

Sewer assets face a great challenge for being underground assets and for experiencing constant deterioration and aging. Reactive decisions are no longer technically nor economically viable, and hence asset managers are migrating to the implementation of proactive strategies. Despite this, managers are making decisions that are poorly justified, based mostly in intuition. This is why it is important to improve the means to implement a more objective and justified proactive approach. Risk-based decisions are a proactive strategy that may help the prioritisation and optimisation Sewer assets face a great challenge for being underground assets and for experiencing constant deterioration and aging. Reactive decisions are no longer technically nor economically viable, and hence asset managers are migrating to the implementation of proactive strategies. Despite this, managers are making decisions that are poorly justified, based mostly in intuition. This is why it is important to improve the means to implement a more objective and justified proactive approach. Risk-based decisions are a proactive strategy that may help the prioritisation and optimisation of maintenance and inspection strategies. It requires for its implementation the estimation of probabilities of failure and their consequences. In this thesis, the analysis is oriented on the failure probabilities on sewer systems, especially on understanding the influences of different characteristics of the pipe (explanatory variables) on these probabilities. The outcome of the thesis answers the following research question: “What is the influence of different characteristics on the probability of failure of the sewer pipes?” Two sub-questions were stated to guide the research and help answering the main research question: 1.What defects can lead to sewer structural failure? 2.What physical characteristics make sewer pipes more prone to fail/deteriorate? For the analysis the Dutch municipalities of Breda and Almere facilitated the results of several years of CCTV inspections of their sewers. Due to the lack of availability of collapse records, this study considered a proxy of collapse, which is loss of watertightness on the pipes. Furthermore, defects that potentially cause loss of watertightness are used as a proxy of the loss of watertightness on a pipe. Defects are obtained from the CCTV reports. The first sub-question was answered based on the proxy failure under study. It was found in the literature review ten defects that potentially cause loss of watertightness, which were classified according to the coding of the standard NEN 3399. These defects are: cracks (BAB), break (BAC), defective connection (BAH), intruding sealing material (BAI), displaced joint (BAJ), porous pipe (BAN), soil visible through defect (BAO), void visible through defect (BAP), infiltration (BBF) and exfiltration (BBG). The second sub-question was answered based on some explanatory variables that were available in the dataset of the inspections, which included: sewer system type, materials, shape, diameter, length, and pipe’s above ground material. To answer this question, a descriptive statistical analysis and two survival methods were implemented: a non-parametric and a semi-parametric model. The non-parametric model consists of an extended version of the Nelson-Aalen estimator of the cumulative hazard (ENE) and its derivative the Extended survival estimator (ESE). Implementing ESE, each characteristic was analysed using the aggregate information of the defects that potentially cause loss of watertightness, and each defect individually. This was done to identify the influence in the failure probabilities (the probabilities of occurrence of defects that potentially cause loss of watertightness). The semi-parametric model that was used is the Cox proportional hazard function, used to estimate the risk ratio associated with one unit increase in one of the characteristics under study. Results of the ESE model showed that: The defects displaced joint (BAJ), infiltration (BBF) and defective connection (BAH), are the ones that have more incidence on the loss of watertightness for the two municipalities. Based on the information of aggregate defects it was observed for both municipalities that the median survival probability is past 14 years. Also, the analysis showed that stormwater sewers have a lower survival probability than foulwater sewers, that PVC pipes have a higher survival probability than concrete pipes, and that shorter pipes have a higher survival probability than longer pipes. In the case of the diameters, for the aggregate defects and defects displaced joint (BAJ) and defective connection (BAH), smaller diameters have a higher survival probability than larger ones. But this tendency is the other way around for defects like cracks (BAB), break (BAC) and porous pipes (BAN), where the diameter has a higher survival probability when are larger than when they are smaller. Characteristics shape and above ground material were only analysed for Breda. It was observed that egg-shaped pipes have a lower survival probability than circular shapes, and that pipes with green fields and floor tiles above them have a lower survival probability than pipes that have above asphalt and pavement. For both municipalities, the results of ESE showed that material is that characteristic that influences the most the probabilities of failure. Results of the Cox proportional model showed that: Almere’s results met the proportionality assumption and showed that the characteristics sewer system type and length are the one that influences the most the failure probabilities. Breda’s data is no appropriate to be used with this model, as it does not meet the proportionality assumption. Recommendations of analysing Breda with an extended Cox are given, as this version of the model allows to use time-dependent variables. of maintenance and inspection strategies. It requires for its implementation the estimation of probabilities of failure and their consequences. In this thesis, the analysis is oriented on the failure probabilities on sewer systems, especially on understanding the influences of different characteristics of the pipe (explanatory variables) on these probabilities. The outcome of the thesis answers the following research question: “What is the influence of different characteristics on the probability of failure of the sewer pipes?” Two sub-questions were stated to guide the research and help answering the main research question: 1.What defects can lead to sewer structural failure? 2.What physical characteristics make sewer pipes more prone to fail/deteriorate? For the analysis the Dutch municipalities of Breda and Almere facilitated the results of several years of CCTV inspections of their sewers.
Due to the lack of availability of collapse records, this study considered a proxy of collapse, which is loss of watertightness on the pipes. Furthermore, defects that potentially cause loss of watertightness are used as a proxy of the loss of watertightness on a pipe. Defects are obtained from the CCTV reports.
The first sub-question was answered based on the proxy failure under study. It was found in the literature review ten defects that potentially cause loss of watertightness, which were classified according to the coding of the standard NEN 3399. These defects are: cracks (BAB), break (BAC), defective connection (BAH), intruding sealing material (BAI), displaced joint (BAJ), porous pipe (BAN), soil visible through defect (BAO), void visible through defect (BAP), infiltration (BBF) and exfiltration (BBG).
The second sub-question was answered based on some explanatory variables that were available in the dataset of the inspections, which included: sewer system type, materials, shape, diameter, length, and pipe’s above ground material.
To answer this question, a descriptive statistical analysis and two survival methods were implemented: a non-parametric and a semi-parametric model.
The non-parametric model consists of an extended version of the Nelson-Aalen estimator of the cumulative hazard (ENE) and its derivative the Extended survival estimator (ESE). Implementing ESE, each characteristic was analysed using the aggregate information of the defects that potentially cause loss of watertightness, and each defect individually. This was done to identify the influence in the failure probabilities (the probabilities of occurrence of defects that potentially cause loss of watertightness).
The semi-parametric model that was used is the Cox proportional hazard function, used to estimate the risk ratio associated with one unit increase in one of the characteristics under study.
Results of the ESE model showed that:
The defects displaced joint (BAJ), infiltration (BBF) and defective connection (BAH), are the ones that have more incidence on the loss of watertightness for the two municipalities.
Based on the information of aggregate defects it was observed for both municipalities that the median survival probability is past 14 years.
Also, the analysis showed that stormwater sewers have a lower survival probability than foulwater sewers, that PVC pipes have a higher survival probability than concrete pipes, and that shorter pipes have a higher survival probability than longer pipes. In the case of the diameters, for the aggregate defects and defects displaced joint (BAJ) and defective connection (BAH), smaller diameters have a higher survival probability than larger ones. But this tendency is the other way around for defects like cracks (BAB), break (BAC) and porous pipes (BAN), where the diameter has a higher survival probability when are larger than when they are smaller.
Characteristics shape and above ground material were only analysed for Breda. It was observed that egg-shaped pipes have a lower survival probability than circular shapes, and that pipes with green fields and floor tiles above them have a lower survival probability than pipes that have above asphalt and pavement.
For both municipalities, the results of ESE showed that material is that characteristic that influences the most the probabilities of failure.
Results of the Cox proportional model showed that: Almere’s results met the proportionality assumption and showed that the characteristics sewer system type and length are the one that influences the most the failure probabilities. Breda’s data is no appropriate to be used with this model, as it does not meet the proportionality assumption. Recommendations of analysing Breda with an extended Cox are given, as this version of the model allows to use time-dependent variables.
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This research describes a way to determine the reliability of coastal pump stations - from which their environment is influences by climate change – in time. Last decade, the challenge within the hydraulic infrastructure network shifted the focus from expanding the infrastructure inventory towards the maintenance and management of the existing network. The reason for this tendency is that the predominant part of the Dutch infrastructure inventory is approaching its end-of-life while their functions are still required. As a consequence, the asset owner is confronted with the challenge to choose the suitable maintenance action in order to extent the assets life-cycle. ... Read more

Infrastructure asset networks form a vital part of all economies worldwide. Although failure of road, rail or water infrastructures can have a huge impact on society, governments are under constant pressure to reduce, account for, and justify expenses. So too for the costs of the construction and maintenance of the infrastructures networks. The effective and efficient management of the performance of these infrastructure assets is therefore an important topic for (governmental) asset management organisations. Recent developments in the field of asset management, such as the introduction of the ISO55000 for Asset Management, show an increased interest in an integral approach to asset management (The Institute of Asset Management, 2014) and having a clear alignment of strategic mission, vision and goals and operational activities – line-of-sight – is promoted as an essential part of the performance management for asset management organisations. “Brownfield” asset management organisations, i.e. pre-existing organisations with already some forms of performance management systems and a history in asset management, are now increasingly looking to professionalize their systems, similar to the suggested developments in literature... ... Read more

Performance-based maintenance contracts (PBMCs) have been experimented with worldwide by government agencies, and have increasingly been adopted to outsource highway maintenance to the private market (NCHRP, 2009, p. 8; Porter, 2005, p. 3). This includes the Netherlands (Rijkswaterstaat, 2014). The use of performance contracts for maintenance is relatively new and agencies encounter numerous difficulties in working with these contracts. Many studies exist on the topic of performance contracts, but studies specifically aimed at understanding the problems in performance-based maintenance contracts are few (Sultana, Rahman, & Chowdhury, 2012, p. 288). This research contributes to filling that knowledge gap, by researching performance-based maintenance contracts used for highway maintenance. The Dutch highway network grew significantly during the 60s and 70s. Many new kilometres of highway, bridges, and viaducts were constructed to accommodate the growing traffic needs (Rijkswaterstaat, 2007, p. 7). Most of those assets are nearing the end of their technical lifespan in the years after 2020 (Goldenbeld, Dijkstra, Aarts, & Schermers, 2016, p. 11; Rijkswaterstaat, 2017, p. 22). This wave of aging infrastructure that the Netherlands is facing in the coming years was the reason for this research to focus on the maintenance of the Dutch highway network... ... Read more

The pioneers in the early 21th century who built the first big offshore wind farms now have to compete with the quickly improving renewable energy technologies and see their farm being out-dated (See also: Dvorak, 2013 & Wind Energy Update, 2013). At present, wind farm owners face difficult decisions when finding the right O&M contract for their offshore wind farm after the warranty period with the original equipment manufacturer (OEM) has ended. Because of a lack of experience in this new O&M phase, decision-making processes are not yet structured or standardized. During the warranty period of approximately 5-10 years, traditional performance-based contracts based on availability guarantees are offered by the turbine manufacturer. To stimulate innovation and increase the energy output, some O&M activities may be better off outside the scope of the performance contract and need a different sourcing scenario. This leads to the aim of this research to compose a decision-making flowchart that can be used when finding a new sourcing strategy for the O&M of offshore wind farms in the post-warranty future. It was concluded that these O&M activities can be segmented in three main items: the offshore turbine maintenance activities, offshore logistics and the onshore back-office maintenance operations. Increasing the maintenance efforts will improve the overall availability of the wind farm but will also increase the required resources to be devoted to O&M. For this reason, it is important to know the cost-drivers for the main O&M activities (Milborrow, 2010). Insights in these costs-drivers and performance shapers were combined and used as input for the decision-making tool. Next, three decision-making variables were derived from the Transaction cost theory and Agency theory that structures the outsourcing decision including the type of contract. First, the owners’ techniques and processes that are needed to transfer or take in-house a good or service were identified as the ‘proprietary nature’ which is an important decision variable when choosing between the O&M in-house or outsource option. Secondly, when outsourcing with a performance-based contract, a relatively high level of knowability of the performance is required compared to behaviour-based contracts. Thirdly, it was found that the type of contract is influenced by the dynamics of the environment because if the performance requirements change due to new innovations, the performance outcome becomes difficult to measure. The three decision-making options altogether lead to four scenarios that could offer a possible sourcing strategy after the warranty period: The Broker scenario, The Incubator scenario, The Coordinator scenario and The Controller scenario. The decision-making flowchart and the four post-warranty sourcing scenarios contribute to a more efficient scoping of the current performance-based maintenance contract in the post warranty future, so that O&M costs can be minimized while keeping the performance high. ... Read more

The cities of Tenggarong and Samarinda in East Kalimantan are in need of a new source of drinking water, since their current source, the Mahakam river, is said to be polluted. The client of this project, Arsari Enviro Industri, owns a large concession named ITCI of a partly degraded forest 90 kilometers East of Samarinda. This report suggests several design possibilities how to capture water in the ITCI concession area and how to transport it to the aforementioned cities. These design possibilities are based on hydrological and geological research. Additionally, the financial, technical and social feasibility of these solutions is evaluated. From the technical and social analyses it was found the project is feasible. However, during the financial analysis it became apparent that without external or government party involvement it is not feasible. ... Read more

Maintaining infrastructure asset systems can be challenging for public authorities since we are living in a time where there is an increasing rate of deterioration of infrastructure assets such as tunnels, bridges and streets. This is due to the ageing and the increased use of these assets. As a result, some assets need additional maintenance measures, besides the regular maintenance, to keep them from failing. However, there is a limited budget making it impossible to invest simultaneously in each aging asset. As a solution, the asset manager can prioritize the numerous assets in order to know in which asset needs to be invested first. The sophistication of this prioritization strategy ranges from ‘observations’ via extended asset maintenance logs and logical reasoning down to more complex prioritization strategies which make use of risk assessment. Asset managers can use risk assessments to prioritize investments in the maintenance of their assets by assessing the risks of the assets’ failure. The risk of an asset failure can be defined as the probability of failure times the impact of failure. The higher the risk value attributed to the asset, the more critical the asset is assumed to be.

In practice, however, risk assessments of assets don’t always yield sufficient information to support a prioritization process and help decision makers to decide which investment in maintenance for which asset is necessary first. It appears that to be able to successfully conduct the risk assessment and prioritize maintenance, the asset manager must connect with two actor groups whose perspectives and interests have a big influence on the process which seeks to identify critical assets. One actor is the asset owner, whose interests towards assets are expressed at a strategic level and who speaks a non-technical, political language, has a long-term point of view and cares about social accountability. The service provider on the other hand speaks a technical, non-political language, has a short-term point of view and cares primarily about the functioning of the assets. So, these actor groups do not speak the same language, use different time perspectives and have diverging interests. Thus the asset manager has a challenging position and needs to translate content between these strategic and operational levels. This friction strongly affects the extent to which the asset manager can claim any degree of control over the process of identifying risks of all assets.

A literature review yielded many methods to identify the critical components of an object, which is necessary for determining the necessary maintenance measures to prevent risks. Nevertheless, no method in literature explains how asset managers can identify critical objects using risk assessments. However, such a method is required when an asset manager wants to prioritize objects of an infrastructure system in order to determine which object needs additional maintenance measures first to treat the current risks.

The objective of this research is therefore to develop a systematic process model for the asset manager to identify the critical public infrastructure objects that simultaneously complies with the interests of the three management levels involved in the asset management process: the asset owner, the asset manager and the service provider. This model is presented in an IDEF0 model, a type of process model, which shows the necessary activities, inputs, outputs, mechanisms and controls underlying the risk assessment process.
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