Intuitive decision-making for wastewater network asset management (2019)
Type of ContentTheses / Dissertations
Thesis DisciplineCivil Engineering
Degree NameMaster of Engineering
PublisherUniversity of Canterbury
AuthorsThorne, Jamesshow all
This thesis argues that expert intuition is useful and even necessary for decision-making within the complex systems of wastewater network asset management (WNAM), and that opportunities for learning are introduced when this intuition is documented, leading to more skilled decision-making over time. A new methodology for documenting intuition is developed involving a survey of 43 wastewater industry experts with the results applied to a decision tree model to determine priorities for action.
Local Councils and other wastewater network asset owners face many challenges in their responsibility to maintain and expand infrastructure networks, subject to aging and degradation, in an environment of increasing public expectation for levels of service, sustainability and management of risks. The high public cost for wastewater infrastructure reinforces the need for effective decision-making and the relevance of targeted research in this area.
The literature review demonstrates that the high-level principles of advanced wastewater asset management are well understood and are provided in guidelines such as the International Infrastructure Management Manual and ISO 55000 Asset Management. However, the specific practical applications of these principles are variable and subjective.
This research examines the socio-technical nature and inherent complexity of WNAM, including the issues of interconnectedness, multiple perspectives, poor data availability and outcomes that are difficult to predict.
Intuition is a mode of decision-making that enables decisions to be made in the face of uncertainty. Further literature review shows that intuition is necessarily used within WNAM decision-making but can be subject to either skilled or unskilled application. Research literature in psychology is used to elaborate on the intuitive process and to demonstrate that unskilled intuition is subject to inherent bias and heuristics that distort decision judgements. Documenting intuition can provide the learning opportunities needed to support the skilled application of intuitive decision-making. The literature review lastly looks at the various methods for documenting intuition within the context of WNAM decision-making.
Two case studies are used to find evidence of intuition decision-making within existing WNAM systems. The first case study examines two different methodologies employed by the Stronger Christchurch Infrastructure Rebuild Team (SCIRT) and shows intuition used “up front” and at the “coal face”. The second case study looks more closely at how intuition is documented through the formal decision-making process adopted by the Waimakariri District Council for their wastewater inspection and renewal planning.
The remaining sections of this thesis detail original work developing a methodology for documenting intuition using a survey of 43 wastewater industry experts. A 1 – 5 Likert-type scale is used to capture the expert’s weighting of significance that they place on a range of factors relevant to WNAM. The results of the survey are analysed and fed into a decision tree model where the effect of each factor can be seen on the overall decision outcome.
When combined with factor scores, the documented significance from the survey enables prioritisation of decisions for WNAM. The process also identifies the factors to include or not include in decision-making and can be used to prioritise data collection or further work defining expert intuitive judgements.
The methodology provides a documentation trail so that the original decision model framework can be repeated or passed on. Wastewater network asset managers can use the documentation as a reference for future learning opportunities, therefore becoming more skilled in intuitive decision-making.